Musashino Terrace

The Musashino Plateau (武蔵野台地, Musashino daichi^?), also translated as Musashino Platform, is a large tableland, known as a fluvial terrace, in the Kantō region of Honshu, Japan. Much of western Tokyo, between the Tama River to the south and the Arakawa River to the north, is built on the plateau. Its northern section is located in southern Saitama Prefecture. It consists of an alluvial fan formed by an ancient River Tama with a layer of volcanic ash, many metres deep, on top.

...
Wikipedia