The Rio Maú ou Ireng is a significant river flowing through the state of Roraima in northern Brazil, forming part of the vast Amazonian watershed. This river originates in the Pakaraima Mountains, an extension of the Guiana Shield, and flows through remote and largely pristine rainforest terrain. Its headwaters are characterized by clear, fast-flowing waters over rocky substrates, transitioning as it moves through the lowland Amazon basin. The river's course defines a portion of the international border between Brazil and Guyana, adding to its unique and remote character. As a tributary within the Amazon system, it supports a diverse aquatic ecosystem typical of the region's blackwater and clearwater rivers.