The Macacu River 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. The basin of the Macacu River is partly protected by the
Bacia do Rio Macacu Environmental Protection Area, part of the
Central Rio de Janeiro Atlantic Forest Mosaic. The Macacu River flows through a flat region of mangroves in the
Guanabara Ecological Station before discharging into the east of
Guanabara Bay near the city of
Rio de Janeiro. ==See also==