Shalbatana is not the only outflow channel in this region. In fact, the southern circumferential region of the Chryse Planitia basin is characterized by the outlets of Mars’ largest outflow channels, which converge radially into the lowlands. Outflow channels are always found in combination with chaotic terrain, a labyrinth of irregular mesas and hills, like Chryse Chaos and Hydraotes Chaos (see context map). Shalbatana Vallis’ source region is the approximately 100-kilometer large impact crater named Orson Wells in the Xanthe Terra highland region (see context map) which is also characterized by chaotic terrain.