Mars has another volcano, Asia Mons. The South Pole of Mars has carbon dioxide ice, and perhaps ice made of water. That Martian landmark looks like a mouth and eyes. It was really an eroded hill. There is a canyon on Mars called Valles Marineris, which is 2,500 miles long.
Some scientists think they saw a dry riverbed on Mars.
These are the surface features. Mars has a thin atmosphere. Mars has a lot of craters. The planet also has desert storms and dust storms. It has depths up to 23,000 feet.