IBIZA coastlines. Posidonia, an underwater plant now celebrating its 25th anniversary as a World Heritage Site, is responsible for giving these waters their transparency. It is also the oldest liv-ing thing on the planet, born in the Pleistocene and more than 100,000 years old. “Posidonia is the architect of the Mediterranean marine eco-system,” explains Manu San Félix. The marine biologist, under-water cameraman and National Geographic explorer explains that it is a plant like no other in the world. One with a root, stem, leaves and flowers - and not seaweed, which it is often confused with. As a plant, it forms a veritable underwater jungle and is the basis of life for countless species. This organism, so easy to find and so commonplace, measures up to a metre and a half, grows at a depth of between 0 and 30 metres, protects the coastline © Manu_San_FélixMS Un Dive Camp para conocer de cerca esta planta marina. // A Dive Camp to get to know this marine plant up close.