Saitama (city) city boundaries. The western portion of the city lies on the lowland created by the Arakawa River along with those created by small rivers such as the Moto-Arakawa River, Shiba River, and Ayase River. The rest of the area mostly resides on the Ōmiya Plateau lying in the north-south direction. Dispersed in this region, major rivers flow southward, almost paralleling to one another. Saitama has ten wards ("ku"), which were assigned official colours as of April 2005: Saitama's economy is principally constituted by commercial business. The city is one of many commercial centers of the Greater Tokyo area and serves
Kantō Plain these plateaus. Among the plateaus, the Musashino Plateau has the largest stretch of land, extending from the western edge of Ōme to the eastern edge of Yamanote which borders the alluvial plains of the Arakawa and Sumida Rivers. Its elevation gradually declines from west to east, measuring 190 m at Ōme and 20 m at Yamanote. Hills in the Kantō Plain stand on Tertiary strata and rise higher than surrounding plateaus, exemplified by the Sayama Hills and Tama Hills, typically, undulating between 100 and 200 m above sea level. Hills located at the western edge of the Kantō Plain, the