Mount Roraima ( , also known as Tepuy Roraima and Cerro Roraima; ) is the highest of the Pakaraima chain of tepui plateaus in South America. First described by the English explorer Sir Walter Raleigh in 1596, its summit area is bounded on all sides by cliffs rising . The mountain also serves as the triple border point of Venezuela (85% of its territory), Guyana (10%) and Brazil (5%).