Guyana, on South America's northern coast, is 85% covered by the Guiana Shield's ancient highlands, with the Pakaraima Mountains in the west peaking at Mount Roraima (2,835 m)—a tepui table mountain shared with Venezuela and Brazil—from Precambrian sandstone 1.7 billion years old. The Kanuku Mountains in the Rupununi savanna rise to 1,400 m, forming tepui plateaus with 1,000 waterfalls. Formed by stable craton and tropical weathering, these ranges feature Kaieteur Falls (226 m)—world's largest single-drop—on the Potaro River (240 km). Coastal plains at 2 m elevation host mangroves along 459 km shore. Iwokrama Reserve preserves 3,716 km² rainforest with 1,500 tree species and giant river otters.
