Príncipe's beaches are important nesting sites for leatherback and hawksbill sea turtles, which come ashore between October and March to lay their eggs. Guided night excursions to watch nesting females or the emergence of hatchlings are available through local conservation organisations and guesthouses. The Fundação Príncipe runs monitoring programmes on the main nesting beaches; their guides are the most knowledgeable about current activity.
The experience requires patience and a willingness to wait in darkness on the sand — there are no guarantees of a sighting, and the turtles must not be disturbed with torches or noise until a guide gives the signal. When it works, watching a two-metre leatherback haul herself above the tide line under a sky full of stars, with no other lights visible in any direction, is one of the more remarkable things you can do in this part of the world.