The Amenthes quadrangle contains parts of the Martian southern highlands and northern lowlands, as well as the transition between the two. In the southern part of the quadrangle, Cimmeria and Tyrrhena Terrae form rugged, cratered plateaus as high as 1 km above datum, which are gouged by the long, linear depressions of Amenthes Fossae. Highland terrae in this quad are separated by Amenthes Planum, an elongate, topographic basin that is located as much as 1 km below the highlands. The northern part of the Amenthes quadrangle consists of southern Utopia Planitia, over 4 km below datum. The western part of the quadrangle is made up of eastern Isidis Planitia, which is nearly as low in elevation. Both Utopia and Isidis Planitiae – which are centered outside of the Amenthes quadrangle – are plains of sediments that fill very ancient impact basins. Various scarps and depressions mark the surface of these lowland planitiae. From south to north, the highland–lowland boundary is defined by distributed fields of knobs and intervening plains of Nepenthes Mensae, rolling plains of Nepenthes Planum, and isolated and coalesced depressions of Amenthes Cavi.