Ilhabela, with 350 km2 Brazils largest island, is part of the Serra do Mar State Park and situated on the northern coastline of So Paulo (see Ilhabela map).

The archipelago of So Sebastio which is composed of 9 islands and some smaller rock formations, was formed about 70 million years ago after the separation of South America and Africa (see Geology). When the Southamerican Plate collided with the Nazca Plate in the Pacific Ocean, tectonic movements on the Atlantic Coast separated part of the mainland forming the archipelago of So Sebastio and Ilhabela. Aside from its biological richness Ilhabela also provides some significant cultural heritage in form of its local caiara communities.
After the discovery of the archipelago by Americo Vespucio, Portuguese conquerors expelled the local Tamoios-Indians and settled on the continent facing side of the island. Until today both, the inner and the Atlantic part of the island are, aside of some isolated fisher communities, widely undeveloped.

85% of Ilhabelas territory is declared sate park preserving dense Atlantic Rainforest which covers 14 summits between 600 and 1.300 m, more than 300 waterfalls, mostly difficult to access and 43 almost deserted beaches.