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
Olympus Mountain Running Olympus Mountain Running Since 1986, nearly every year, various initiators organize marathons in the Olympus Mountains in Greece. For these Olympus Marathons the classic distance of 42.195 kilometers provides a clue to the distance of some of the runs in the Olympus. Starting in 2010, events established that surpass the classic marathon distance. In some races, runners run over distances of 57 km, 70 km or almost 100 km. At the stations along the route, the runners are provided with drinks and snacks and mostly medical aid. They are offered water, electrolytic drinks, bananas, salty biscuits, sandwiches, chocolates and more.