Extending for 2,347 km from the tripoint with Colombia to the tripoint with Guyana, the Brazil–Venezuela boundary mostly follows the watershed between the Amazon and Orinoco river systems through sparsely-populated highland areas. The boundary was delimited in general terms in an 1859 agreement, and the alignment was clarified through protocols that were signed in 1905, 1912, and 1928. The boundary has been demarcated with more than 2,900 monuments by an active mixed boundary commission.