The Essequibo, at approximately 1,010 kilometers, is the largest river in Guyana and the third-largest river in South America by volume of discharge after the Amazon and the Orinoco.

Its headwaters in the Pakaraima Mountains include the drainage from Roraima’s summit.

Water on the Brazilian portion eventually reaches tributaries of the Amazon — specifically the headwaters of the Rio Cotingo and related rivers that ultimately flow into the Rio Branco and then the Amazon proper.

The Amazon system, of course, is the world’s largest river by volume of discharge and the drainage basin with the greatest biodiversity in the world.

The fact that a single mountain summit drains into all three of these great river systems is not merely a geographical curiosity.