Margaritifer Terra (/ˌmɑːrɡəˈrɪtəfər ˈtɛrə/) is an ancient, heavily cratered region of Mars. It is centered just south of the Martian equator at 4°54′S 25°00′W / 4.9°S 25°W and covers 2600 km at its widest extent. The area reveals "chaos terrain", outflow channels, and alluvial plains that are indicative of massive flooding. Wind erosion patterns are also in evidence. A region within the terra shows some of the highest valley network densities on the planet. Ares Vallis is another notable feature, where the flood and flow patterns are in evidence; it was the landing site of the Soviet Mars 6 lander and NASA's Mars Pathfinder. It is also one of several proposed landing sites for the Mars 2020 Rover.