The Forest gericinó mendanha is a large natural area, roughly 170 square miles in size, which is located between the cities of Mosque, Nova Iguaçu and the western neighborhoods of Rio de Janeiro (Bangu and Campo Grande).

The separate forests contained within this area are the Sierras Marapicu, Mendanha and Madureira and the parks of Mendanha, Ecological Park Mendanha, Gericinó-Mendanha, Nova Iguaçu and the Massif Gericinó and  Nova Iguaçu Volcano.

The first attempts to put this area under protection date back to the 1930s but did not see any movement again until the mid 1960s with the adoption of the Forest Code of 1965.  It was yet another 20 years until the late 1980s that the suggestion of turning some of this area into a State Park occurred.