Olympus Mons is a very large shield volcano on the planet Mars.
Olympus Mons has a height of nearly 22 km (13.6 mi or 72,000 ft.), standing about two and a half times as tall as Mount Everest's height above sea level on Earth. It is the tallest mountain of all planets and other rounded bodies in the Solar System, and is the second tallest mountain in the Solar System overall, after Rheasilvia on the Asteroid Vesta.
The volcano is located in Mars's western hemisphere at approximately 18.65°N 226.2°E, just off the northwestern edge of the Tharsis bulge. The western portion of the volcano lies in the Amazonis quadrangle (MC-8) and the central and eastern portions in the adjoining Tharsis quadrangle (MC-9).