The South Pole-Aitken basin.

this is becase the moon powers its self

South Pole-Aitken basin - Moon - Diameter: 2,500 km http://en.wikipedia.org/wiki/Impact_crater#Largest_named_craters_in_the_Solar_System --Geoffrey A. Landis

South Pole Aitken Basin (diameter 2500km) is not the largest known impact crater. That distinction lies with Utopia Planitia Basin (3500km) on Mars. However, SPA is the deepest known impact basin in the Solar System at 13 kilometers.

If proven, the hypothesized Borealis basin, on Mars, would be the largest impact basis, at more than 10000 km in diameter.

The name of the continent at the South Pole is Antarctica.