Curieuse Island lies just two kilometres off the north coast of Praslin, a 15-minute boat ride from the main jetty. It is a Seychelles national park and one of only two places in the world where the coco de mer grows wild (the other being Praslin's Vallée de Mai). The island is also home to a managed population of Aldabra giant tortoises — over 300 of them wander freely through the palm forest, and they are entirely unafraid of humans, which makes close encounters routine.
The snorkelling around Curieuse Marine Park is excellent. The shallow bay and rocky reefs hold hawksbill turtles, reef sharks, rays, and dense populations of reef fish. Day trips from Praslin are straightforward — numerous boat operators run tours that combine a walk through the tortoise sanctuary, lunch on the beach, and snorkelling on the reef. A half-day is enough; a full day on the island is luxurious.