Ngorongoro Crater

Ngorongoro Crater lies within the Ngorongoro Conservation Area in Arusha Region, northeastern Tanzania, about 180 kilometers west of Arusha City, and is considered the world's largest inactive, intact and unfilled volcanic caldera. It formed when a large volcano, estimated to have once stood between 4,500 and 5,800 meters tall, erupted and collapsed in on itself between two and three million years ago; the resulting crater floor covers 260 square kilometers and sits 610 meters below the rim. Ngorongoro Volcano was one of eight extinct shield volcanoes within the Eyasi half-graben, active from roughly 2.45 to 2 million years ago, and is composed primarily of basaltic trachyandesite rock. The conservation area around it was established in 1959 and designated a UNESCO World Heritage Site in 1979. This entity documents Ngorongoro Crater specifically as a geological formation, the world's largest intact, unfilled volcanic caldera left by a collapsed shield volcano.