九十九里浜
Sanmu is located in the northeastern part of Chiba prefecture, about 30 kilometers from the prefectural capital of Chiba and about 60 to 70 kilometers from the center of Tokyo. It is included in the urban employment area of Tokyo metropolis. Most of the city is located in the flatlands of the Kujūkuri Plain, which runs from the center to the south of Kujūkuri Beach, one of Japan's leading sandy beaches, and faces the Pacific Ocean for about 8 kilometers.