Ridley turtles nest here en masse from July to December, a process that is called an “arriabada” is Spanish. Most eggs are laid after sunset and before dawn. You can take tours that will allow you to watch sea turtles come ashore to lay their eggs, or see the baby turtles emerge from their eggs. Ostional villagers sometimes come to the rescue of baby sea turtles and guard against vultures as the baby turtles make their way to the sea.

Playa Ostional is protected by the Ostional Wildlife Refuge. Local conservationists have proposed that a controlled harvest will help preserve the population since Costa Ricans look forward to the sea turtle egg harvest and consider the eggs a delicacy. Visitors, however, must not disturb the turtles or their eggs in any way.