Ishigakiyama Ichiya Castle (石垣山一夜城 Ishigakiyama Ichiya-jō) is located in Hayakawa, south-east of Odawara City in Kanagawa Prefecture. The castle was constructed in 1590 by Toyotomi Hideyoshi during the Siege of Odawara on a mountain originally called Kasagakeyama. It is also known as the "one-night castle" (一夜 ichiya). It was not actually constructed in one night but in - still respectable - 80 days by 40,000 workers and stonemasons who had been brought in from Kyūshū and who had been previously employed at the castles of Azuchi and Osaka.

The castle was not conceived as a temporary structure but as a well-fortified base for a prolonged siege of Odawara. Once the castle was completed, Hideyoshi's troops felled the trees that had concealed the site. Due to the secrecy surrounding the construction, the besieged Hōjō troops in Odawara Castle were led to believe that the castle was built overnight. Whatever psychological effect the castle had, the Late Hōjō surrendered to Toyotomi Hideyoshi and his allies after a three-month siege.

These stones were found at the Hayakawa stone quarry and used to build the walls of Edo Castle.

Hideyoshi and his generals had gathered some 250,000 soldiers, effectively blockading the castle by land and by sea. Nine days after the castle was completed, the Hōjō laid down their arms. Ishigakiyama Castle was abandoned after their surrender. Nowadays, the former castle grounds are a National Historic Site. In 2017, the castle was listed as one of the Continued Top 100 Japanese Castles.

It was at Ishigakiyama that Hideyoshi held parties with his concubine Yodogimi (淀君, 1567-1615), had tea ceremonies with Sen-no-Rikyu and met Data Masamune who had been refused to send his troops to Odawara and expected to be executed by Hideyoshi.

Stairs leading up to the second bailey (二の丸 ni-no-maru).

The second bailey

Stairs leading up to the main enclosure (本丸 honmaru).

The inner bailey (本丸 honmaru).

A small shrine in the honmaru.


View of Odawara and its castle from the honmaru.

The site of the former donjon.

View of the valley north of the castle that leads up to Hakone.

The three photos above show the well of Ishigakiyama Castle.

Nishikuruwa (西曲輪, the western castle compound)

Minamikuruwa (南曲輪, the southern castle compound)

Map of the castle

A computer-generated image of Ishigakiyama Ichiya Castle.

View of Ishigakiyama as seen from Odawara castle.

More pictures in the Ishigakiyama Ichiya Castle album.


The historical path up to the castle starts at Hayakawa Station (早川駅, one station from Odawara). It takes about 45 minutes to reach the castle site. The path leads mostly uphills and is lined with historical descriptions (all in Japanese).

If you come by car via the Odawara-Nishi Interchange, follow the signs to the Ishigakiyama Castle Historical Park (石垣山一夜城歴史公園). A paved yet narrow road leads right up to the castle. There is a parking lot next to Yoroizuka Farm that can get quite crowded on weekends and holidays.