624 km in diameter, approx the size of the state of Arizona and 27Km high; about three times Mount Everest. The scarp rim around the base is several Km high itself.
From Wikipedia: Olympus Mons
QUOTE (Wikipedia)
a person standing on the surface of Mars would be unable to view the upper profile of the volcano even from a distance as the curvature of the planet and the volcano itself would obscure it. The only way to view the mountain properly is from orbit
Anyone want to go for a hike? It doesn't look too steep at least.

