Known throughout Costa Rica is the Leather back Turtle. Most commonly known to lay eggs in Playa Grande which is a protected beach area now. However many other spots in Costa Rica do they come up to shore to lay eggs. Playa Grande in December seems to be the best spot if you want to see it.
The leather back turtle starts as tiny hatch lings and end up to live as long as 30 to 50 years. They are considered to be the largest of all sea turtles. Their numbers have dropped by a lot and many conservation efforts are working to save them. Even pictures of local Costa Rica ticos have been found to take the eggs in large numbers for their family. Probably something that has been happening for thousands of years. However government, parks and protectors of the species are stepping in due to the shortage of their numbers. However, If your going in December its a must see and the local park in Playa Grande runs the showing.