The Rio negro ( black river) is the largest left tributary of the Amazon river. The largest Blackwater River in the world and one of the worlds 10 largest rivers.

It was discovered in 1638 by Pedro Teixeira a Portuguese explorer.The river was named for its black color which results from vegetal debris, not sediment. The Rio Negro is connected with the Oronoco basin by the Casiquiare, a natural canal. An important commercial channel “rubber and nuts are shipped on it”.p