The Highest Volcano in the Solar System

Olympus Mons, 25 kilometres high, is the highest volcano in the Solar System
It has the highest volcano in the solar system, Olympus Mons which stands at 26 kilometres above the surrounding plain: Mount Everest is only one third as high.

Olympus Mons lies at the western edge of another gargantuan feature, the Tharsis dome which is a 10 kilometre-high, 4000 kilometre-wide bulge in the Martian surface.