Açuã River

The Açuã River (Portuguese: Rio Açuã) is a river of Amazonas state in north-western Brazil, a tributary of the Mucuim River.

The river flows through the Mapinguari National Park, a 1,776,914 hectares (4,390,850 acres) conservation unit created in 2008. To the north of the national park it is crossed by the Trans-Amazonian Highway (BR-230), then runs through the Balata-Tufari National Forest, where it joins the Mucuim.