The area has a number of unusual features, which are thought to be quite old because of the high crater density. The crater inside Hellas has been filled with material, which may be related to volcanic activity on the basin's northwestern rim. It also might be related to the presence water and water ice. However, there is evidence elsewhere that the ground here is rich with ice.
HiRISE will be used to investigate this in more detail when the basin is free from atmospheric dust.