Although the Mount Roraima plateau is shared between Brazil, Guyana and Venezuela the highest point is entirely within Venezuelan territory.
Mount Roraima (Spanish: Monte Roraima [ˈmonte roˈɾaima], also known as Tepuy Roraima and Cerro Roraima; Portuguese: Monte Roraima [ˈmõtʃi ʁoˈɾajmɐ]) is the highest of the Pakaraima chain of tepui plateaus in South America.:156 First described by the English explorer Sir Walter Raleigh during his expedition in 1595, its 31-square-kilometre (12-square-mile) summit area:156 is bounded on all sides by cliffs rising 400 metres (1,300 ft). The mountain also serves as the triple border point of Venezuela (85% of its territory), Guyana (10%) and Brazil (5%).:156
Mount Roraima lies on the Guiana Shield in the southeastern corner of Venezuela's 30,000-square-kilometre (12,000-square-mile) Canaima National Park forming the highest peak of Guyana's Highland Range. The tabletop mountains of the park are considered some of the oldest geological formations on Earth, dating back to some two billion years ago in the Precambrian.
The highest point in Guyana and the highest point of the Brazilian state of Roraima lie on the plateau, but Venezuela and Brazil have higher mountains elsewhere. The triple border point is at 5°12′08″N 60°44′07″W, but the mountain's highest point is Maverick Rock, 2,810 metres (9,219 ft), at the south end of the plateau and wholly within Venezuela.Provided By: https://en.wikipedia.org/wiki/Mount_Roraima