Geography of Mars Aurorae Sinus. The largest dark feature seen from Earth is Syrtis Major Planum. The shield volcano, Olympus Mons ("Mount Olympus"), rises 22 km above the surrounding volcanic plains, and is the highest known mountain on any planet in the solar system. It is in a vast upland region called Tharsis, which contains several large volcanos. See list of mountains on Mars. The Tharsis region of Mars also has the solar system's largest canyon system, Valles Marineris or the "Mariner Valley", which is 4,000 km long and 7 km deep. Mars is also scarred by countless impact craters. The largest of
Erebor Mons Erebor Mons Erebor Mons is a mountain on Titan, the largest moon of the planet Saturn. It is located near Titan's equator, between 4-5° south and 35-36° west, centered on , in the western part of Quivira region. It is 40 km across, more than 1 km high and has lobate flow features to its north and east. It is probably a cryovolcano. Erebor Mons is situated about 470 km to the north-northeast of a larger cryovolcanic construct, Doom Mons. Erebor Mons is one of the highest known mountains of Titan, but it is not readily discernible on radar or