Olympus Mons ( Latin for Mount Olympus) is a very large shield volcano on the planet Mars. By one measure, it has a height of nearly 22 km (13.6 mi or 72,000 ft).Olympus Mons stands about two and a half times as tall as Mount Everest's height above sea level. It is the tallest mountain in the Solar System. It is the youngest of the large volcanoes on Mars, having formed during Mars's Hesperian Period. It is currently the largest volcano discovered in the Solar System and had been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow").