The Shimōsa Plateau is a plateau on the Kantō Plain in central Honshu, Japan. The plateau covers most of northern Chiba Prefecture. The plateau was historically richly agricultural, but in the 20th century the western and central Shimōsa Plateau became one of the major industrial areas of Japan, as well as a large-scale bedroom community of the Tokyo Metropolitan Region. Narita International Airport is located in the center of the Shimōsa Plateau.

The Kantō Plain , in the Kantō region of central Honshu, is the largest plain in Japan. Its 17,000 km2 covers more than half of the region extending over Tokyo, Saitama Prefecture, Kanagawa Prefecture, Chiba Prefecture, Gunma Prefecture, Tochigi Prefecture, and Ibaraki Prefecture.