Geology of Mars of the dichotomy places a significant constraint on theories of its origin. Straddling the dichotomy boundary in Mars's western hemisphere is a massive volcano-tectonic province known as the Tharsis region or the Tharsis bulge. This immense, elevated structure is thousands of kilometers in diameter and covers up to 25% of the planet’s surface. Averaging 7–10 km above datum (Martian "sea" level), Tharsis contains the highest elevations on the planet and the largest known volcanoes in the Solar System. Three enormous volcanoes, Ascraeus Mons, Pavonis Mons, and Arsia Mons (collectively known as the Tharsis Montes), sit aligned NE-SW along the crest
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