All around Praslin are huge, fantastically shaped rocks, which look like vast Henry Moore sculptures. In comparison, the coral reefs are mere striplings, perhaps six to eight thousand years old and teeming with life; a landscape painted in the myriad colors of living coral, jewel-like shells and an amazing nine hundred species of fish. Much of the interior is virtually virgin forest, in the exquisitely beautiful Vallée de Mai, declared a World Heritage Site by UNESCO in 1984, is the home of the unique coco de mer, vanilla orchids, many species of lizards and some of the earth's rarest birds.

The coco de mer is a fruit from an extraordinary palm tree, which is found in only one place in the world, the Vallée de Mai on Praslin Island. This strange object was much prized over past centuries; philosophers believed it was the fruit of the tree of knowledge, and that it grew under the sea, on account of the fact that it floated as far as the Maldives islands. It gained a reputation as an aphrodisiac, perhaps because of the singular shapes of the male stalk and the female fruit. The Emperor Rudolph II of Hapsburg, towards the end of his life, offered two gold florins for one of those fabulous nuts.