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
Mount Olympus Mount Olympus Mount Olympus (; "Olympos", for Modern Greek also transliterated "Olimbos", or ) is the highest mountain in Greece. It is located in the Olympus Range on the border between Thessaly and Macedonia, between the regional units of Pieria and Larissa, about southwest from Thessaloniki. Mount Olympus has 52 peaks, deep gorges, and exceptional biodiversity. The highest peak, Mytikas (Μύτικας "Mýtikas"), meaning "nose", rises to . It is one of the highest peaks in Europe in terms of topographic prominence. Olympus is notable in Greek mythology as the home of the Greek gods, on Mytikas peak. Mount Olympus is