Elysium Mons is the largest volcanic edifice in the province. It is 375 km across (depending on how one defines the base) and 14 km high. It has single, simple caldera at its summit that measures 14 km wide and 100 m deep. The volcano is distinctly conical in profile, leading some to call it a stratocone; however, given the predominantly low slopes, it is probably a shield. Elysium Mons is only about one-fifth the volume of Arsia Mons.