The Essequibo River is the largest river in Guyana, and the largest river between the Orinoco and Amazon. Rising in the Acarai Mountains near the Brazil–Guyana border, the Essequibo flows to the north for 1,014 km (630 mi) through forest and savanna into the Atlantic Ocean. It has a total drainage basin of 156,828 km2 (60,552 sq mi) and an average discharge of 5,650 m3/s (200,000 cu ft/s).

Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic mainland British West Indies. Guyana is an indigenous word which means "Land of Many Waters". Georgetown is the capital of Guyana and is also the country's largest city. Guyana is bordered by the Atlantic Ocean to the north, Brazil to the south and southwest, Venezuela to the west, and Suriname to the east. With a land area of 214,969 km2 (83,000 sq mi), Guyana is the third-smallest sovereign state by area in mainland South America after Uruguay and Suriname, and is the second-least populous sovereign state in South America after Suriname; it is also one of the least densely populated countries on Earth. It has a wide variety of natural habitats and very high biodiversity. The country also hosts a part of the Amazon rainforest, the largest tropical rainforest in the world.