On the dark beaches of Tortuguero, giant leatherback turtles haul ashore at night to lay eggs in a ritual little changed in millions of years.
Tortuguero's beaches see nesting leatherbacks between March and June, when females that can weigh over 400 kilograms drag themselves out of the surf after dark, dig a metre-deep chamber with their back flippers, and lay a hundred or more eggs in a trance most researchers believe blocks out any awareness of onlookers.
Licensed local guides walk the beach ahead of visitor groups scouting for a turtle already committed to laying, since approaching too early can spook her back to the sea, and torches are red-filtered or banned outright to avoid disorienting her or hatchlings from other nests.
Book through the park's guide system rather than wandering the beach independently — it's not allowed, and for good reason — wear dark clothing, keep phones and cameras off or on night mode only, and expect to wait quietly on the sand for an hour or more before a guide gives the signal to approach.
