A somewhat long and fertile river on the edge of the Jadhai Desert, the River Peko was home to a number of ancient but primitive cultures before the rise of its most prominent autochthonous culture, Pekorova. It was later conquered by the Empire of the Trilui, Sira, and then the Savirai Empire successively, but the wars have done fairly limited damage to the extensive agricultural complexes on either side of the river, which continue to be major grain producing regions.

It is also on the western edge of the Face of the Moon, the desert homeland of the Savirai.