The South Pole–Aitken basin is an immense impact crater on the far side of the Moon. Wikipedia

An immense impact crater on the far side of the Moon. At roughly 2,500 km in diameter and 13 km deep, it is one of the largest known impact craters in the Solar System. It is the largest, oldest, and deepest basin recognized on the Moon; named for two features on opposite sides of the basin: the crater Aitken on the northern end and the lunar south pole at the other end. Wikipedia Disambiguation

Very large impact crater on the southern far side of the Moon Wikidata