Map of the Caribbean/Amazonian area. Marked are waterways and modern borders.
The former and the latter are interrelated: most of the north border of Brazil is formed
by the watershed of the rivers that flow to the Amazon, resp. the Atlantic Ocean. The
border between Venezuela and Guyana is the watershed between the rivers of the Es-
sequibo, resp. the Orinoco system. The other borders are large rivers (Oyapock, Ma-
rowijne and Corantijn). The rivers are the transport routes in this part of the world.