Olympus Mons the height of Mauna Kea as measured from its base on the ocean floor). The total elevation change from the plains of Amazonis Planitia, over to the northwest, to the summit approaches . The summit of the mountain has six nested calderas (collapsed craters) forming an irregular depression × across and up to deep. The volcano's outer edge consists of an escarpment, or cliff, up to tall (although obscured by lava flows in places), a feature unique among the shield volcanoes of Mars. Olympus Mons covers an area of about , which is approximately the size of Italy, and it
Doom Mons Doom Mons Doom Mons is the name of a mountain range and its eponymous peak on Titan, the largest moon of Saturn. A putative cryovolcano, it is the largest mountain range on Titan by volume, and its 1.45 km-high peak one of the highest. It was discovered by the "Cassini–Huygens" probe in 2005 and officially named in 2012. Doom Mons is located in the Southern Hemisphere of Titan, between 14-15° south and 40-41° west. It is located within the Aztlan darklands region, possibly connected to the wider Shangri-La dark region, and is adjacent to Sotra Patera, a possible cryovolcanic caldera