Elysium Planitia, located in the Elysium and Aeolis quadrangles, is a broad plain that straddles the equator of Mars, centered at . It lies to the south of the volcanic province of Elysium, the second largest volcanic region on the planet, after Tharsis. Elysium contains the major volcanoes Elysium Mons, Albor Tholus and Hecates Tholus. Another more ancient shield volcano, Apollinaris Mons, is situated just to the south of eastern Elysium Planitia.