The Elysium quadrangle covers the area between 180° to 225° west longitude and 0° to 30° north latitude on Mars. The northern part of Elysium Planitia, a broad plain, is in this quadrangle. The Elysium quadrangle includes a part of Lucus Planum. A small part of the Medusae Fossae Formation lies in this quadrangle. The largest craters in this quadrangle are Eddie, Lockyer, and Tombaugh. The quadrangle contains the major volcanoes Elysium Mons and Albor Tholus, part of a volcanic province of the same name, as well as river valleys—one of which, Athabasca Valles may be one of the youngest on Mars. On the east side is an elongated depression called Orcus Patera. A large lake may once have existed in the south near Lethe Valles and Athabasca Valles.