Hellas Planitia is a plain located within the huge, roughly circular impact basin Hellas located in the southern hemisphere of the planet Mars. Hellas is the third- or fourth-largest known impact crater in the Solar System. The basin floor is about 7,152 m (23,465 ft) deep, 3,000 m (9,800 ft) deeper than the Moon's South Pole-Aitken basin, and extends about 2,300 km (1,400 mi) east to west. It is centered at 42.4°S 70.5°E. Hellas Planitia spans the boundary between the Hellas quadrangle and the Noachis quadrangle.
Viking orbiter image mosaic of Hellas Planitia
Geographic context of Hellas
Apparent viscous flow features on the floor of Hellas, as seen by HiRISE.
Twisted terrain in Hellas Planitia (actually located in Noachis quadrangle).
In geography, a plain, commonly known as flatland, is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and as plateaus or uplands. Plains are one of the major landforms on earth, being present on all continents and covering more than one-third of the world's land area. Plains in many areas are important for agriculture. There are various types of plains and biomes on them.
The Kakanui Range dominates the eastern horizon of the Maniototo Plain of New Zealand
Montane plains as seen in Horton Plains in Sri Lanka.
A small, incised alluvial plain from Red Rock Canyon State Park (California).
A flood plain in the Isle of Wight.