The deepest point on Mars.
Hellas Planitia is the largest clearly visible impact basin on Mars — about 2,300 km wide and 7 km deep. It is the lowest point on the planet, and the air at its floor is dense enough that liquid water could briefly survive there.
Claim your plot here →Around 4 billion years ago, an asteroid the size of a small country slammed into Mars's southern highlands, punching out Hellas — a crater so vast it could hold several European nations.
Because it is the lowest point on the planet, the thin Martian atmosphere piles up thickest here — nearly twice the surface average. That's just dense enough that, on a warm day, liquid water could exist for a moment before boiling away. It is one of the more Earth-like spots on Mars.
About 2,300 km across — you could drop several countries inside it.
7 km below the surrounding surface — deeper than the Grand Canyon by far.
The densest air on Mars sits at its floor — the best shot at brief liquid water.