We first wrote about Ostional in 2012. Since then, the rules for visitors have become stricter, and that's a good thing for the turtles. Here's how to plan a visit now.
What it is
The Ostional Mixed Wildlife Refuge covers about 85.7 square km of beach, land and sea on the Pacific side of the Nicoya Peninsula, just north of Nosara. It was first protected in 1982 to safeguard the nesting beach of the olive ridley sea turtle. WWF has called it one of the two most important places in the world for the species. For more on the turtles themselves, Costa Rica Journeys has a good primer on the olive ridley sea turtle.
What happens here is called an arribada, Spanish for "arrival." Thousands of female olive ridleys gather offshore and come up the beach over several days to lay their eggs. Each turtle digs a nest with her back flippers, lays roughly 100 eggs, then covers and packs the sand before heading back to sea.
When to go
Arribadas happen several times a year and are linked to the moon cycle, but nobody can give you an exact date months ahead. The largest usually happen in the rainy season, with September and October often the biggest. Dry-season arribadas, from December to June, tend to be smaller and shorter.
The practical approach is to stay nearby for several nights and follow announcements from the refuge and local guides. If turtles are the main reason for your trip, build in flexibility rather than booking a single night.
How visits work
You can't just walk onto the beach during an arribada. Access is limited to visitors with authorized guides from the Ostional community, in small groups. The refuge has said it won't serve visitors who arrive without a reservation, so book with the accredited community guides before you get to the village. Their office is a small building on the main road through Ostional, which leads toward the beach.
Follow your guide's instructions closely. Stay out of the turtles' path, keep your distance, and don't use lights or flash unless your guide says it's fine. The rules tightened after 2015, when crowds of tourists got in the way of nesting turtles.
Getting there and where to stay
Ostional is a short drive north of Nosara on unpaved roads. In the rainy season, when most big arribadas happen, rivers rise and roads get muddy, so a 4x4 is the sensible choice and you should check road conditions locally. Most visitors stay in Nosara, around Playa Guiones and Playa Pelada, and drive up with their guide or arrange transport.
Read our Nicoya Peninsula guide for how Nosara fits into a route, and our wildlife guide for other turtle-nesting beaches, including Tortuguero on the Caribbean side.
Frequently asked questions
When is the next arribada?
Arribadas follow the moon cycle but can't be predicted precisely. Watch for announcements from the refuge and local guides, and stay a few nights to improve your chances.
Do I need a guide?
Yes. During an arribada, beach access is limited to visitors with authorized guides from the Ostional community, booked in advance.
What's the best month?
The biggest arribadas usually happen in the rainy season, especially September and October.
Is there an entrance fee or tour fee?
Visits are arranged through the community guides, who'll tell you the current cost when you book. We don't list prices because they change.
