Elysium Mons is a volcano in the Elysium Volcanic Region. It has a roughly circular caldera with deep channels running down the sides. It was discovered by Mariner 9. "Elysium" refers to a place of reward (Heaven), according to Homer in the Odyssey.  More details about the background for the names of Martian features can be found at How are features on Mars Named?.
The smaller volcanoes Hecates Tholus (to the northeast) and Albor Tholus (to the southeast) are relatively close.
- Blunck, J. 1982. Mars and its Satellites. Exposition Press. Smithtown, N.Y.
- MacDonald, T. 1971. The Origins of Martian Nomenclature. Icarus: 15, 233-240