Tharsis Montes is a range of three volcanoes in the Tharsis region of Mars. It consists of Ascraeus Mons, Pavonis Mons and Arsia Mons, which are arranged in that order from north to south. Another volcano, Olympus Mons, the tallest known mountain in the solar system, is located northwest of the Tharsis volcanoes. Tharsis Montes viewed on Google Mars