Shimōsa Plateau
Kōzaki is located in far northern Chiba Prefecture, approximately 40 kilometers from then prefectural capital at Chiba and 60 to 70 kilometers from central Tokyo. The town faces the Tone River to the north, and sits on the lowlands of the river to the north and the Shimōsa Plateau to the south. Kōzaki is part of Ōtone Prefectural Natural Park.