Welcome to Casa Roja and the Boca del Río Sierpe (the mouth of the snake river). We want your stay here to be as rewarding and safe as possible, so please help us by taking a few minutes to familiarize yourself with your new environment upon arrival. This guide is organized by Health and Safety, Guidelines and Tips Around the House, What to Do at Casa Roja and Beyond, and Osa Peninsula History and Wildlife. (Download Boca Orientation Guide PDF)

All photos taken by Casa Roja and FISHBIO friends and families.

Our Mission

Our team at Casa Roja has a deep love for Costa Rica and a long history of environmental research, education, and conservation. We see the lodge as a unique opportunity to introduce guests to the spectacular natural beauty of the Osa Peninsula, as well as the Sierpe River and its special mangrove forests. At the same time, we strive to support research, education, and conservation in the region by working with communities, universities, and environmental groups. We hope that more people sharing our love and appreciation for this incredible region will help support its preservation for generations to come.

The People and Dogs of the Boca

Argenis, Graciela, and Valentina live at Casa Playa and are here to help you. They will provide you a basic overview of the property on your first day, are always available to answer any questions you may have, and will work to ensure you have the best possible experience at Casa Roja. They will respect your privacy at the house, and will stop by in the mornings and evenings at pre-arranged times to help you plan your day. They will work with you to determine your desired level of assistance with meals and housekeeping. Use the twoway radio (or WhatsApp) to contact Argenis and Graciela if you need anything. Call them immediately if there is a health concern, an animal in the house, or any other emergency.

Argenis is originally from Guanacaste in the northwest of Costa Rica, but has lived around Sierpe for about 20 years. Before becoming the caretaker at Casa Roja, he worked with horses on a number of fincas (ranches) in the area, and then in the tourism industry in Sierpe. He’s incredibly apt at spotting wildlife, imitating the calls of animals found along the Río Sierpe, well known and respected locally, and knows the river like the back of his hand. His favorite things about the boca are the sun, sand, sea, and tranquility.

Graciela has spent her whole life in southern Costa Rica. Born in Golfito, she has lived and worked in San Vito, Drake and Sierpe before moving to the boca. She enjoys preparing and sharing the culinary delights that Costa Rica has to offer for guests. Graciela appreciates the uniqueness and natural beauty of the boca environment, loves the fact that there are more animals than people, and sees the boca as a place where the fast pace, stress and problems of the modern world matter very little.

Valentina lives at the boca with her parents, loves the ocean and playing in the waves on a surfboard! She gets particularly excited when families with children close to her own age come to visit, and delights in accompanying them on excursions, especially when watermelon, oranges and grapes are brought along as snacks. When there are no visitors at the boca, she enjoys horseback riding and playing games online.

Marvin is our nearest neighbor and he is enthusiastic about sharing the boca environment with you. He only speaks a little English, but he tries hard and loves to learn. He will be happy to show you how the locals fish, take you on a hike to the waterfall, walk you along the rocks to the beach at Playa Marvin, or accompany you to Playa Ganado. There are a number of hazards around the boca, and it is very helpful (and sometimes reassuring) to have Marvin nearby. Ask him to harvest and open a coconut for you or show you where the cacao beans grow!

Pelusa, Sophie, and TingTing are a few of the boca dogs. All of the dogs are friendly, but please let us know if you are uncomfortable around dogs. They help keep animals out of the house at night and help alert us to snakes on hikes. Consider them assets and encourage them to follow you when you wander from the house.

Health and Safety


Here you will also find insect repellent, tools, batteries, and various household items. If you are looking for anything, start by checking in the storage containers under the kitchen bar. There are also supplies in the bottom kitchen drawers. If you can’t find what you need, ask Argenis or Graciela. If not found on site, they can arrange to have things delivered to Casa Roja, sometimes on the same day.

Always be aware of your surroundings. We don’t want to scare you, but you are in the heart of the rainforest and encounters with potentially dangerous animals are a possibility. Crocodiles have been spotted on the beach and are common in the Sierpe River, mangroves, boca, and ocean. Poisonous snakes have been found on the property. Potentially even more hazardous than the animals are extreme environmental conditions you may encounter, such as intense sun, torrential rain, lightning and strong tides.

Call Argenis immediately if you have any health or safety concerns. Transportation to local medical facilities is possible, but challenging given our remote location. The nearest medical clinic is located in Drake Bay, a 45-minute boat ride from Casa Roja. Ebais Medical Center in Agujitas de Drake is open Monday, Wednesday, Thursday, and Friday from 7:00 a.m. to 5:00 p.m. (Phone: +506-2775-1975). There is also a hospital located just over an hour away from Casa Roja, via riverboat and car/ambulance, in Ciudad Cortes. Hospital Tomás Casas Casajús (500 norte de la Ecuela Ojo de Agua) provides 24-hour emergency services (+506-2786-8148).

Being informed and aware of your safety can help you enjoy a safe, relaxing, and unforgettable stay at Casa Roja and the Boca del Río Sierpe.

The Sun

The tropical sun is one of Costa Rica’s biggest assets, but also one of its main hazards! Far too many visitors underestimate the intensity of the sun near the equator and end up with painful sunburns, or worse. Please make proper sun protection a priority throughout your stay! Don’t let cloudy skies fool you, even on overcast days you can end up red, dehydrated, and miserable without proper planning.

Too much sun leaves you feeling drained and reduces your enjoyment. Sunburn, heatstroke, and dehydration are serious issues for foreign travelers visiting Costa Rica who are not used to the heat and humidity of the tropical climate. Taking precautions to avoid exposure to the sun will greatly improve your travel experience. We have various types of sunscreens for your daily use, so apply liberally and often. Zinc-based options are more environmentally friendly, as they do not damage coral reefs. Because of Casa Roja’s open-air design, it is still possible to get sunburned at the house, even on a cloudy day. Long sleeved shirts, long pants, a broad brimmed hat and plenty of sunscreen are your best defenses against the sun!

Over-exposure to the sun and excessive sweating can lead to heat exhaustion or heatstroke. These conditions have similar symptoms, which can include light-headedness or dizziness, fatigue, confusion, thirst, an increased heartrate or breathing, and hot, dry skin that is flushed but not sweaty. Heat stroke can be serious, and even deadly, so ask for help and try to take some simple first-aid steps at the first sign of these symptoms. These include getting the affected person to a shady area and trying to cool them down as quickly as possible, such as by removing clothing, applying cool water to the skin and fanning, or applying ice packs to the armpits or groin area. To prevent dehydration, drink plenty of water and sports drinks to balance electrolytes. Avoid excessive coffee, caffeinated tea, soda and alcohol, which can all contribute to dehydration.

Dehydration influences how you feel physically at the end of the day. This is especially true when guests are reluctant to drink water when traveling by boat and going on tours without bathrooms. Please don’t make the same mistake – drink lots and lots of water! We provide various canteen options and a variety of drinks, including fresh coconut water. Carrying a bottle of cold fruit drink encourages you to drink more during the day. Look in the cupboards for powdered drinks, including low-calorie options.

Animals and Plants

After the sun, protection from biting insects should be your next priority. Luckily, the same long-sleeve shirt that protects you from the sun also works for bugs (that, and insect repellent). Generally, the most bothersome insects at Casa Roja are sandflies (no-see-ums), but mosquitos can be bothersome anywhere else you venture, so always be prepared. Sandflies are sporadic but definitely the worst during new and full moon periods. You know you’ve been bitten by a sandfly if you feel a bite but don’t see anything at first. Look closely and you’ll see a black speck, the source of the pain. Sandfly bites appear as little red bumps in anywhere from minutes to hours after the bite. Anti-itch cream (located in the first aid kit and bathrooms) can help reduce itching, but prevention is key.

Crocodiles have been spotted on the beach and are common in the Sierpe River, mangroves, boca, and ocean, so always use caution when entering the water. American crocodiles aren’t typically aggressive and attacks on human are infrequent in Costa Rica, but they do happen. Avoid swimming at night and avoid excess splashing.

23 of the 140 different snake species in Costa Rica are venomous. Some snakes live in tree tops, while others prefer rocks or ground cover, and they often blend in amazingly well with their environment. Again, be mindful, stay alert and look before you step, grab, sit, or lay down to make sure there aren’t any snakes hiding there! The venomous fer-de-lance has been encountered on the Casa Roja property. Closed-toed shoes that cover your ankles are recommended at all times when walking or hiking, and knee-high rubber boots (which we provide) are required when walking the Casa Roja property or nearby jungle.

Larger, less bothersome, wildlife abounds at Casa Roja as well. With any luck, you may see coatis, capuchin and howler monkeys, crocodiles, sloths, anteaters, agoutis, peccaries, poison dart frogs, butterflies, iguanas, macaws, toucans, and many other animals. Those lucky enough to spot any of these animals must not attempt to feed, approach or touch them – they are wild, and should remain that way!

The plant diversity on the Osa Peninsula is perhaps even more astonishing. Many plants are incredibly beautiful, some are edible, others are poisonous! Several of the plant species growing in the vicinity of Casa Roja have thorns or sharp-edged leaves. Enjoy walks through the forest with open eyes, and do not eat any nuts or fruits you find in the forest, unless Casa Roja staff confirms that it is safe! Coconuts, mangos, papayas and even cacao can be eaten fresh off the tree – ask Argenis or Marvin to show you where they grow!

The River and the Ocean

Be aware of large waves, strong tides and fast currents! Statistically, drowning is your number two risk in Costa Rica (after driving), and since you won’t be driving at Casa Roja, it is now your number one risk. Please use caution entering the river or ocean around the boca. Outgoing tides are especially dangerous since you, your kayak, or boat can be quickly swept out to sea. Argenis will advise you on currents and tides, and point out the best – and safest – spots to get in the water. Please be sure to let Argenis know when and where you are planning on swimming or using kayaks or other equipment.

Guidelines and Tips Around the House

In the House

No paper products in the toilets, please! Casa Roja is an environmentally sensitive location, so please help us keep our septic systems operating effectively. Dispose of all paper products in waste paper baskets and take advantage of our high-tech toilet technology. There are airtight containers in each bathroom where you can find miscellaneous toiletry items.

The security cameras are installed for your safety. However, we understand that some people are uncomfortable with cameras, especially around the house. Video files are not viewed off-site, but stored to a local hard drive and only viewed by you or Argenis, if the need arises. Feel free to cover the camera in the main living room if you feel it intrudes on your privacy.

Help us conserve the environment by conserving power and being prudent with food and drinks. It takes significant resources to get supplies to Casa Roja, so please use them wisely by finishing drinks and open containers, and not leaving food out to spoil. Similarly, it takes a substantial amount of power to keep your supplies frozen, cold or fresh. Please be mindful to fully close refrigerator/freezer doors. Water is abundant but hot water takes natural gas to heat, so use hot water wisely. Towels can be used more than once by hanging them up to dry. We change sheets and provide general laundry service upon request.

Try to charge electronics during the day and unplug items at night. During the day, the solar energy system produces enough power to recharge our house batteries and your electronics. At night, electronics can drain the house batteries and result in the need to run a gas-powered generator, which we prefer to avoid. It is okay to charge items at night when needed for tours the next morning. Place devices in airplane mode to save power.

Turn the fans off when they’re not needed. Casa Roja is solar powered and battery storage is always challenging, so please try to conserve energy by turning off fans and other appliances when not in use.

Please remember to turn off unnecessary lights! For the same reasons we ask you to limit charging of electronics to daylight hours, please remember turn off lights around the house when you don’t need them. It is especially easy to forget turning outside lights off, or – if you’re up before sunrise – overlook that they’re still on when it gets light!

Insects are attracted to light, so keep them off or low when possible. The overhead lights in the house are bright and energy efficient, but don’t create much ambiance. The four hanging lights outside the screen create a nice ambiance and enough light to move about in the living area. Use the LED candles to light bedrooms and baths and help you move about the house in soft light. Leave the lights off in bedrooms when not in use. Always have a flashlight handy.

Keep bedroom doors closed in the evenings and nights. Even on bug-free nights (which is most of the time), a variety of insects can be flying about, especially if the screens are open and lights are on. Keep bedroom doors closed, especially in the evenings and at night. This will ensure you sleep soundly without being bothered by mosquitos and sandflies, and also reduces the chances of encountering creepy-crawlers during bathroom visits. Sleeping with the fans on keeps you cool and the bugs off you.

Lightweight long-sleeved shirt and pants are your best protection against sandflies, since bug repellent doesn’t really seem to work. Burning bug repellent coils may help a little, but, if you suspect sandflies are going to be a problem, close the screens sooner rather than later, usually in the evening as the sun is setting. Sandfly bites result in itchy red bumps that are bothersome, so take precautions.

Don’t throw towels and clothes on the floor and keep your luggage zippered. Scorpions, spiders and bugs seek out places to hide, so don’t let them into your things. Put things you would like washed out back, rather than on the floor. Stand shoes up against the wall, tips up.

Keep sand outside the house as much as possible. If you bring sand and dirt into the house, you or someone else has to remove it eventually. Prevention is key! Use the footbath or the outdoor shower to rinse off outside. Put wet clothes, sandy clothes and towels on the outside counter.

Place sandy towels and clothing on the outside sink to be rinsed prior to placing in the washing machine. Argenis and Graciela will take care of all laundry needs for you, or feel free to use the washing machine in the bodega as needed. We like to do laundry in the morning and let clothes air dry during the day, rather than use the dryer.

Close the bedroom blinds in the afternoon to keep the sun out and the rooms cooler. The bedrooms heat up in the afternoon, but much less so if you close the west-facing blinds. Close the blinds and doors in the morning when you leave for day.

You will find that small changes in location can dramatically influence temperature, humidity, wind, and insects. On days with a nice breeze you can enjoy reading and lounging at Casa Roja throughout the day. On warmer days with no breeze, it can get a little warm in the afternoons. Turn on fans and close the front screen for a little more protection from the sun. Argenis will place lounge chairs for you under the palms near the beach, a good place to have a drink, read, and nap…

Rubber boots are your friends. You’ll notice locals wear rubber boots everywhere, all day long, and for good reason. Snakes blend in well to the surrounding leaf litter, and poisonous snakes are found throughout Costa Rica. Boots are your best protection, and are available for you to walk around the property behind the house or go on the forest trails. Although your inclination may be to slip boots on barefoot, it’s a sure recipe for blisters. Wear socks, and if you’re walking the beach to Playa Ganado, anticipate that your boots and socks will get wet – it’s part of the adventure! Boots are suitable footwear for rocky beach points around the boca, or south of Playa Marvin. The rocks along the river and ocean are slippery and dangerous to walk on. If you walk on them, please wear footwear such as boots, which provide decent traction, and ankle and leg protection.

Boots are suitable footwear for rocky beach points around the boca, or south of Playa Marvin. The rocks along the river and ocean are slippery and dangerous to walk on. If you walk on them, please wear footwear such as boots, which provide decent traction, and ankle and leg protection.

Don’t wander too far from the house at night, and carry a flashlight. Please pay attention to your surroundings. Don’t wander away from the house at night without Argenis, boots, and a flashlight.

When you leave for the day, remember to bring water, sunscreen, sunglasses, bug repellent, hat, rain jacket, binoculars, and snacks. There are drybags and backpacks located around the house for your use.

In the Kitchen

Casa Roja staff will assist you with food preparations according to your preferences.

Guests are typically on their own for breakfast. You will find the kitchen stocked with fresh fruit, fresh eggs from our chickens, bacon and sausage from a local farm, plantains, tortillas, cheese, coffee and tea, and we recommend relying mostly on these fresh, locally sourced staples. We have found the flavor and quality of most dairy products in Costa Rica a bit disappointing, but can make yogurt & Co. available upon request.

For lunch and throughout the day, especially if involves lounging around the house and beach, guests are typically happy making tacos, snacking on home-made tortilla chips and fresh salsa, experimenting with fruit cocktails, and generally enjoy their privacy around the house. On days that include activities, such as early morning mangrove tour, perhaps with a stop on the way back for a jungle hike and a swim on a remote beach, Graciela will gladly pack a lunch for you or have something prepared when you return.

Graciela usually prepares dinner for our guests on most nights, but of course you are welcome to cook your own food on your schedule if you wish. Graciela’s dinners range from traditional Costa Rican dishes (comida típica) to Italian-inspired comfort food. Freshly caught fish from the river or ocean are obviously among our favorites, and snapper and dorado (mahimahi) are plentiful. For carnivores, we definitely recommend a beach BBQ during your stay! We’re sure you’ll enjoy the various cuts of local beef, pork, and chicken, basted with home-made Casa Roja marinade, cooked slowly over a wood fire on the beach. There’s usually plenty of food to enjoy leftovers for a couple of days (our favorite!).

Tap water is safe to drink. There’s a variety of sizes of insulated reusable water bottles in the cupboards for you to use throughout your stay. Our tap water is sourced from two streams in the pristine jungle on the property, triple-filtered and UV treated prior to reaching the house.

Put food away and clean counters and dishes after food and drink preparation. Keeping the Casa clean and orderly increases your enjoyment by reducing insects and unpleasant encounters with animals. Ants, the clean-up crew of the rain forest, are attracted to most foods and will quickly swarm around edibles left on the counter or fallen on the floor! Keep the sinks clean and empty drain traps. Wipe counters often. Clean up spills and pick up crumbs as you notice them. Put dirty kitchen towels on the outside counter to be washed later.

Minimize chances of animal encounters at the house during the night. Make sure the kitchen, BBQ, and fish cleaning station are clean and all food has been removed. Put beer, wine, soda cans and bottles in the outside recycling container.

You will find a traditional Costa Rican coffee maker, a chorreador (“dripper”), in the kitchen. It may seem a bit cumbersome at first – it takes a few minutes to make a fresh cup, and grounds need to be emptied – but you will probably like it after you get used to it. After all, who knows better about preparing a great cup of coffee than Costa Ricans? Start with about 2-3 tablespoons for the first cup, then add an additional tablespoon for each additional cup. Pour the water in slowly and be patient. When it’s full or you want to start with fresh grounds, rinse the grounds out in the foot rinsing station outside. Coffee and tea are under the counter in an airtight container.

Coconut water can be poured over ice, mixed into cocktails, used for cooking, treating wounds, basically everything in Costa Rica. The only thing wrong with this ultimate drupe (fruit/nut/seed) is how hard they are to open! Please don’t risk injury. Ask Argenis or Marvin to open coconuts for you. They also delight in teaching people how to safely get to their delicious content – watch, learn, and then give it a try!

Costa Rican Limes are the greatest fruit on the planet, and the best ones grow wild, across the river, on Isla Violín. The Costa Rican lime is a well-kept secret, but Argenis will gladly take you across the river to pick some! Add to cocktails, use in ceviche, cucumber salad, as salad dressing, in beer, over avocado, on tacos, with tequila, … use your imagination!

Plantains make cooking breakfast worth it! A staple for Costa Ricans, plantains are eaten and cooked in a variety of forms and dishes throughout the year. Plantains are best when ripe and fried on the grill or in a pan until golden and crispy. A ripe plantain looks like a rotten banana, but the worse the plantain looks, the sweeter it is! Graciela would love to introduce you to this local staple, prepare some for you, or show you how to do it yourself!

On the Beach and Around the Boca

Mosquitos generally aren’t a problem at Casa Roja; however, be prepared when you go to the beach, waterfall, jungle, or mangroves (basically everywhere else). Apply bug repellent, and wear (or at least take) protective clothing if you go anywhere.

If you venture down to the beach and shaded palm area, be prepared for mosquitoes and sandflies, no matter what time of day it is. Sandfly bites can be extensive before you realize it! Be especially aware of your ankles and feet, apparently their preferred food.

All beaches in Costa Rica are public, including the ones around Casa Roja. Tour boats and other tourists may be present at any time, but if they stop by, it’s usually in the early afternoon.

Equipment, Tools and Other Resources

Rubber boots. Have we mentioned there are rubber boots for you to use at the house? Yes, they’re that important, we can’t tell you enough. If you wear other shoes, they should have sturdy soles and be able to withstand mud and water. In the forest, on the trails and remote parts of the property, or on excursions to nearby places such as Isla Violín, please wear the botas (rubber boots)! Walking sticks are also provided.

While most of the rain falls from May through October, there is a chance of being caught in a downpour any time of the year. Here in the tropics, rain often falls hard and heavy, turning creeks into torrents in a matter of minutes. Those who travel lightly – without water−sensitive equipment − have little to worry about, but when packing guidebooks, valuable documents, camera equipment, or other electronics it is advisable to make use of one of the waterproof dry bags provided at Casa Roja.

The two-way radios are the best way to get in touch with Argenis or Graciela, or to communicate amongst yourselves if the group splits up. Note that these radios work in close range (such as from the house to the beach) but will not provide communication with people at Casa Roja while on a tour off-site.

Flashlights are essential for moving around the boca in the dark. A selection of flashlights and headlamps are found under the counter in the kitchen, along with batteries. If there is even a remote chance you may not return to the house until after dark, please bring a flashlight or headlamp.

The Nikon zoom binoculars are great for watching the boats pass the boca. Keep them on the table for quick access and take the wildlife binoculars with you on hikes or to the beach. You will see a variety of boats going by the boca all day long, and much of the traffic is predictable. Regular shuttles carrying tourists between Sierpe and Drake Bay navigate the mouth around the same time each day. Other boats may be heading to the offshore fishing grounds, dive locations or to the mangroves.

The spotting scope can also be used to view Isla Violín and the surrounding boca. It should be out and on a tripod, but if it isn’t, locate it on the shelf or ask Argenis to set it up.

We have a variety of books on Costa Rican wildlife, plants, culture, local history and geography available to read and peruse. Some may be on coffee table, others can be found in airtight bins on the shelf.

The selection of fishing tackle available at the house will cover all the needs of novice and advanced anglers. Whether you just want to catch some dinner with a handline on the beach, cast lures to barracuda, fly fish for jacks, or troll nearshore for dorado, we have you covered. Argenis and/or Marvin will delight in showing you the best spots and techniques, from shore or by boat. Please treat the equipment as if it were your own, rinse with freshwater after use, and store appropriately when you’re done fishing for the day. For those wanting to pursue sailfish, tuna and other offshore species, we can arrange for an fishing guide to pick you up for a day on the high seas (guide rates apply).

Kayaks, surfboards, boogie boards, and other water and beach equipment are available to use. As mentioned above, check with Argenis before going into the river or ocean. He will help you with the equipment, provide tide information, and let you know where and when it’s best to go in the water.