關東平原
The eastern side, part of the Kantō Plain, can be further divided into nine separate expanses of hills and ten plateaus. The former occupy small areas neighboring the Kantō Mount Range, including the Hiki Hills and Sayama Hills. The latter are mainly surrounded by alluvial flood plains. In the southeastern portion of the prefecture, the Ōmiya Plateau stands in a southeastward direction, sandwiched by the Furutone River to the east and the Arakawa River to the west.