In the heart of Praslin, the Vallée de Mai Nature Reserve is a 19.5 ha area of palm forest which remains largely unchanged since prehistoric times. Dominating the landscape is the world's largest population of endemic coco-de-mer, from a palm-tree once believed to grow in the depths of the sea, is the largest seed in the plant kingdom.
The coco-de-mer is a flagship species of global significance as the bearer of the largest seed in the plant kingdom. The forest is also home to five other endemic palms and many endemic fauna species. The Vallée de Mai is the only area in the Seychelles where all six species occur together and no other island in the Indian Ocean possesses the combination of features displayed in this nature reserve. The ancient palms form a dense forest, along with Pandanus screw palms and broadleaf trees, which together constitute a unique ecosystem.
The natural formations of the palm forests are of distinctive natural beauty with dappled sunlight and a spectrum of green, red and brown palm fronds. Shaped by geological and biological processes that took place millions of years ago, the reserve is an outstanding example of an earlier and major stage in the evolutionary history of the world's flora.
The Vallée de Mai constitutes a living laboratory, illustrating of what other tropical areas would have been before the advent of more advanced plant families.