Leatherbacks, known as baulas in Costa Rica, are the largest of the world's seven species of sea turtles, averaging 350 kg. and more than a meter and a half in length. Watching one of these great ancient beasts come ashore at night to continue the age-old tradition of nesting in tropical sands is a very moving experience for most people, although others find the two-hour process a bit more than their patience and interest levels can tolerate.

In Costa Rica, this species can be found nesting at a number of beaches on both coasts, however, two of the more heavily used beaches are Playa Grande (Big Beach) and Playa Langosta (Lobster Beach), to the north and south, respectively, of Tamarindo Beach. Together, the aforementioned two beaches make up Las Baulas Marine National Park.

The nesting season at Las Baulas extends from October through February. When away from their breeding sites, leatherbacks range widely throughout the world's oceans searching for their principal food, jellyfish.