The reason why this castle is called “Ishigakiyama Ichiya-jo” (Ichiya-jo means a castle built in one night), is said to be that, when Hideyoshi Toyotomi decided to build the castle, he commanded to cut off the trees of the nearby forest just in one night, and use it to built the frameworks of the the wall and the oar of the castle. After that, he put white papers upon the frameworks to make it looks like the real white stone wall of the castle. It is said that the soldier lurked in the Odawara-jo castle seen the while walls and felt there is no hope to win the war.

The General Toyotomi Hideyoshi, held tea ceremonies is called Sen no Rikyu and concubine, the Noh Yodogimi from this castle. He also welcomed the envoy of the Emperor at here.

This ground is registered as a national park area and the country designated historic spot.

        ・About 40-minute walk from JR Hayakawa Station via Kampaku Farm road.

        ・About 50-minute walk from Hakone Tozan Railway Iriuda Station

          Parking lot …Free of charge, can park many cars (about 50 cars)