Olympus Mons — Olympus Mons is the tallest mountain in the solar system, at 25 km. Located on Mars, and officially called by its Latin name Olympus Mons.
It is named for the mountain on Earth. Olympus Mons is an apparently extinct shield volcano, the result of highly fluid magma flowing out of volcanic vents over a long period of time, and is much wider than it is tall; the average slope of Olympus Mons’ flanks is very gradual.
The Hawaiian islands are an example of similar shield volcano volcanoes on a smaller scale.
Olympus Mons is located in the Tharsis bulge, a huge swelling in the Martian surface that bears numerous other large volcanic features.
Among them are a chain of lesser shield volcanoes including Arsia Mons, Pavonis Mons and Ascraeus Mons, which are small only in comparison to Olympus Mons itself.
Olympus Mons is located at approximately 135W by 20N.