Tharsis is the giant volcanic plateau on Mars that includes Olympus Mons. It is one of the planet’s most prominent geological regions and contains several enormous shield volcanoes.
The Tharsis region rises several kilometres above the surrounding northern lowlands and stretches across a vast area near Mars’s equator. Besides Olympus Mons, its major volcanoes include Ascraeus Mons, Pavonis Mons, and Arsia Mons. The region also contains extensive lava plains and tectonic features.
Scientists associate Tharsis with long-lived volcanic activity and major crustal deformation. The immense weight of its volcanic deposits affected the Martian crust and may have influenced the planet’s geological history. Tharsis is distinct from Elysium, another important volcanic province farther east. The name is also related to the broader Tharsis rise, while individual volcanoes within it retain their own names.