evidence: Satellite map of Courantyne River - In Guyana Map of Courantyne River The Courantyne/Corentyne/Corantijn River is a river in northern South America in Suriname, it is the longest river in the country. The river originates in the Acarai Mountains and flows northward for approximately 724 km (450 mi) between Guyana and Suriname, emptying into the Atlantic Ocean near Corriverton, Guyana and Nieuw Nickerie, Suriname.