[1] Inamura Castle was located on Shiroyama Hill, at an elevation of 64 meters, overlooking the entrance to Tokyo Bay.

The modern city of Tateyama spreads five kilometers to either side of this castle, but when it was built in the Muromachi period, the jōkamachi was a small settlement on the shore near this location.

The surrounding area was a well-water region suitable for rice cultivation and was near the ancient provincial capital of Awa Province.

By the end of the 15th century, the Satomi were firmly in control, and construction of Inamura Castle began in 1486 and was completed after his death in 1491, but these dates are not confirmed.

In response, Satomi Yoshitoyo launched an amphibious invasion of Kamakura, in the process of which his forces burned down the famed Shinto shrine of Tsurugaoka Hachiman-gu.