The Vredefort crater is the largest verified impact crater on Earth. More than across when it was formed, what remains of it is in the present-day Free State province of South Africa. It is named after the town of Vredefort, which is near its centre. Although the crater itself has long since been eroded away, the remaining geological structures at its centre are known as the Vredefort Dome or Vredefort impact structure. The crater is calculated to be 2023 ± 4 million years old, with impact being in the Paleoproterozoic Era. It is the second-oldest known crater on Earth.