Olympus Mons, located on Mars, is the largest volcano in the solar system, with a base that could cover a large area and a peak that rises significantly above the surrounding plain. The volcano's height is reported to be nearly 22 kilometers above the surrounding plain, which is almost three times the height of Mount Everest. Its status as an active or extinct volcano is unclear, with some reports suggesting it may not be extinct and others noting recent volcanic activity on Mars.