Chiba borders Ibaraki Prefecture to the north at the Tone River, Tokyo and Saitama Prefecture to the west at the Edo River, the Pacific Ocean to the east and Tokyo Bay around its southern boundary. Most of Chiba lies on the hilly Boso Peninsula, a rice farming region: the east coast, known as the Ninety-Nine League Plain, is an especially productive area. The most populous zone, in the northwest of the prefecture, is part of the Kant? region that extends into the urban agglomeration of Tokyo and Saitama.
Chiba is linked to Tokyo by several railway lines: the main trunk lines are the Keiyo Line and Sobu Line. The Musashino Line connects Chiba to Saitama and northern Tokyo. Southern Chiba is connected to Kanagawa Prefecture by the Tokyo Wan Aqua-Line bridge-tunnel.