evidence: The Essequibo is a river flowing through Guyana in South America and is the country's largest river and the continent's third largest. It has its source in the Acarai Mountains near the Guyana-Brazil border, from where it flows for 630 miles to drain into the Atlantic Ocean. Along its length, the river nourishes vast swathes of forests and savanna. The Essequibo River flows through mountains and valleys, with the Guiana Moist Forests ecoregion dominating the landscape in its basin. Before entering the ocean, the river passes through Guyana's largest city and capital, Georgetown. From there, it flows for 13 miles to the sea. [...] After several conflicts, Guayana, along with the Essequibo River, was brought under the leadership of the British Empire. After this period, the Essequibo River territory became a region of contention between Guayana and Venezuela (which borders Guayana to the west). While both nations signed a treaty in 1899, Venezuela still contests the treaty as unfair.