The channel of Casiquiare is an exceptional natural formation. It is about a channel connecting the Orénoque to the the Amazon, via the Rio Negro, thus making communicate two rivers and two basins slopes by crossing the Watershed.

Located at the Venezuela, length of more than 200 km, it is at the beginning only one arm of Orénoque, which joined Río Guainía to form Rio Negro.

Lope de Aguirre borrows it at the time of its mutiny in 1561, perhaps without suspecting its discovery.

Certain geographical maps reveal it at the 18th century, Condamine (inter alia) affirming its existence. Humboldt goes up it in 1800 and a precise description.

External bonds

• Alexander von Humboldt and the Casiquiare To rivet
• http://www.carishina.com/articles/casiquiare.html