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 (14 mi). Olympus Mons stands almost three times as tall as Mount Everest’s height above sea level. It is the youngest of the large volcanoes on Mars, having formed during Mars’s Amazonian Period. It had been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for “Olympic Snow”). Its mountainous nature was suspected well before space probes confirmed its identity as a mountain.