Castle30 September 2026

Ishigakiyama Castle: Hideyoshi's 'one-night castle' above Odawara

Castle

Ishigakiyama Castle (石垣山一夜城)

Built by

Toyotomi Hideyoshi

Location

Odawara, Kanagawa

Type

Mountain castle (yamajiro)

Designation

National Historic Site

Japan's Top 100 Castles (sequel list)

No. 126

In 1590 Toyotomi Hideyoshi brought the largest army Japan had ever seen to Odawara, the seat of the Hojo clan who had ruled the Kanto for five generations. Odawara Castle was built for a long siege, so Hideyoshi built a castle of his own on the hill across the river — stone walls and all, in about eighty days. When it was finished his men cut down the trees that had hidden it, and to the defenders below it looked as if a castle had appeared overnight. The Hojo surrendered that summer, and with them the last rival to Hideyoshi’s rule of Japan.

That hill is Ishigakiyama, “stone-wall mountain”, and the castle is known as the Ichiya-jo — the one-night castle. It’s one of the Continued Top 100 Japanese Castles, and it pairs perfectly with Odawara Castle (one of the original Top 100) on the same day.

The view from the top

The main enclosure (honmaru) sits about 260 m up, and from the lookout you see the whole stage of the siege at once: Odawara town and its castle below, the Hakone hills behind, and the curve of Sagami Bay running east towards Chigasaki and Enoshima.

This is the part to take slowly. Picture the Hojo castle town ringed by Hideyoshi’s allies. Tokugawa Ieyasu, who would go on to found the Edo shogunate, held the east side, across the town. The rest of the army closed in from the north. And down at the Hayakawa gate, on the south side, Sengoku Hidehisa — hero of the manga Sengoku — fought the battle that won back his lord’s favour. Standing where Hideyoshi stood, you can see why he chose this hill: nothing in Odawara was hidden from it.

There’s a less dignified story, too, and Japanese audiences love it: Hideyoshi and Ieyasu standing side by side on this hill, relieving themselves towards Odawara Castle, while Hideyoshi offers Ieyasu the whole of the Kanto once the Hojo fall. Historians doubt it happened here, but it has become a favourite scene in period dramas and manga. And Ieyasu did take the Kanto. He moved his capital to a small fishing town called Edo, and the rest is Tokyo.

The castle itself

Walk the loop around the enclosures before you leave. Unlike most siege camps, this one was built in stone, by the same masons who worked on Azuchi and Osaka. Much of it tumbled in the great Kanto earthquake of 1923, and the collapsed walls are left as they fell — which gives you a rare look at how these walls were put together. The well enclosure (ido-kuruwa), down in a hollow below the main walls, still holds water.

Cake with a view

By the car park is Ichiya-jo Yoroizuka Farm, run by Tokyo pâtissier Toshihiko Yoroizuka. The cakes are the real thing, the terrace looks out over the orchards to the sea, and after the walk up it earns its place in the day.

If you go

• Pair it with Odawara Castle: castle and museum in the morning, then up to Ishigakiyama for lunch and the view — or the other way round, so that you know the view before you visit the castle below.
• Winter mornings are clearest; that’s when Sagami Bay looks its best.
• Trainers are fine by taxi. Walking up from Hayakawa, bring water.

If you’re staying at Chigasaki Southern Beach Resort & Residence, this is an easy half day on the way to Hakone — or on its own, back in time for sunset on the beach.