It is one of the most important reserves of the Atlantic shrub (a short, branchy and woody plant) in Brazil, located at the Isla Grande, in the southern littoral of the state of Rio de Janeiro.

Two areas of preservation where created within the island with the objective of protecting this rare natural riches: the Isla Grande and the Provincial Biological Reserve of the Southern Beach.

Both are ecosystems covered with mangroves, necks of sandy or rocky grounds under shallow water, and a short, intricate and dense vegetation.

The 3600 hectare biological reserve occupies one third of the island and is the subject of diverse scientific investigations; it is besieged by tourists captivated by its dazzling landscapes.

Fossilized human remains found here revealed they were 3000 years old according to tests run with carbon 14. The warrior tribe of the Tupinambás and the Tamoios controlled the region when the first Portuguese arrived to the area. The leader of the former, called Cunhambebe, spread terror amongst the colonizers for he used to behead the Europeans.

The zone was a pirate hideout during those times as well, many of whom ended up settling in the region.

The tourists will find vestiges of the facilities and homes of the whale hunters, an activity which peak lasted until the second half of the XIX century only.

A small town worth of visiting is the village of Aventurro, built by the descendants of the old whale hunters who wedded the local natives.

One of the best preserved mangroves of the State of Rio de Janeiro is found at the reserve. The Capivari River cleaves through a territory that has been altered by the interference of the people.