The Vredefort Crater is the largest impact crater on the planet. It is located in South Africa and originally had a diameter of 300 km (190 mi), but has since eroded away and is now roughly 70 km (43 mi).
The crater was formed from an asteroid colliding with the Earth with a diameter of more than 10 km (6 mi) around 2 billion years ago.
Since then, the crater and its ejecta have been removed by weathering and erosion. The visible evidence that remains today includes A) deformed rock units that were once below the crater’s floor; B) small-scale impact evidence such as transformed mineral structures and shatter cone structures; and, C) a dome of uplifted rock that once formed a central peak within the crater.
The Vredefort Impact Crater is the largest asteroid impact structure that still has visible evidence at Earth’s surface. It is also the second-oldest impact structure with visible evidence at Earth’s surface. Only the Suavjärvi Crater in Russia is older.