下総台地
Lake Teganuma originally occupied a large area to the north of the plateau, but has narrowed in modern times due to being sealed off from the Tone River and land reclamation projects. Teganuma historically covered , but after land reclamation now covers . Lake Inbanuma was created by the natural damming of a small valley in the Shimōsa Plateau, and originally covered . After land reclamation projects, similar to those carried out on Teganuma, it now covers .