The Bacia do Rio Macacu Environmental Protection Area (APA) covers parts of the municipalities of
Cachoeiras de Macacu,
Itaboraí and
Guapimirim in Rio de Janeiro. It has an area of . It includes areas of plains and lowlands and mountainous areas with springs and important remnants of forest. Its largest area is occupied by pastures, vegetable fields and quarries for sand to be used in construction. The Guapimirim-Macacu sub-basin is part of the Guanabara Bay basin. It is bounded to the north and northwest by the
Serra dos Órgãos, to the northeast by the Serra de Macaé de Cima, to the east by the Serra da Botija and the Serra de Monte Azul, and to the south by the Serra do Sambê and the Serra dos Garcias. The
Macacu River, the main river of the APA, is born in the Serra dos Órgãos at about in the municipality of Cachoeiras de Macacu, and runs for about to its junction with the Guapimirim River. Protected areas near the APA include the
Serra dos Órgãos National Park with ,
Três Picos State Park with ,
Paraíso Ecological Station with ,
Guapimirim Environmental Protection Area with and
Petrópolis Environmental Protection Area with . Most of these were created to protect springs and headwaters in the forested mountains as well as biodiversity. ==History==