5.1431°N, 60.7625°W.
Tepui (table mountain) at the triple border of Venezuela, Brazil, and Guyana, in the Pakaraima range of the Guiana Highlands. The summit plateau is 31 km², bounded on all sides by 400-metre vertical cliffs of Precambrian sandstone (~2 billion years old) — making the tabletop one of the oldest exposed geological surfaces on Earth. The cliffs were formed when the surrounding softer rock eroded away, leaving the harder cap rock as an elevated island. The plateau receives 4,000 mm of annual rainfall with persistent cloud cover, isolating its endemic biota for tens of millions of years; many of the small carnivorous plants, frogs, and insects on the summit exist nowhere else. Mount Roraima inspired the lost-world novel by Arthur Conan Doyle (1912). The first ascent was made in 1884 by Everard im Thurn via the natural sloping ledge (La Rampa) on the Venezuelan side.
A sandstone tabletop eroded out of the surrounding landscape two billion years ago has been an island in the air long enough for its frogs to evolve into species nowhere else on Earth.