Odawara Castle

Why is the keep made of concrete?

The tower you climb at Odawara is not old. It was finished in May 1960, ninety years after the castle was formally abolished, and it is built of reinforced concrete. Inside, it is a museum with display rooms, not a set of bare timber floors.

Visitors who have read about Japan’s twelve surviving wooden keeps often arrive expecting one of them. Odawara is not. Knowing that before you buy a ticket changes what you look for once you are up there.

What the 1960 rebuild copied, and what it invented

The rebuild was not guesswork. The city worked from an Edo-period hinagata (a scale model) and hikizu (construction drawings) made when the keep was rebuilt in the Hōei era, so the outline you see follows a documented design. The structure is a compound keep — three roofed storeys over four floors, with an attached turret and a connecting turret — standing 38.7 m above the ground with a floor area of 1,822 m².

One thing is new. The railed balcony running around the top floor was added in 1960 and did not exist on the Edo-period keep. The official site says so plainly. It is the best single detail to look for if you want to see where the copy stops and the twentieth century begins.

The money is part of the story too. The rebuild cost 80 million yen and was funded partly by a public campaign called kawara ichimai undō — “one roof tile each” — in which townspeople donated toward the tiles. The keep went up as a civic project for the city’s twentieth anniversary, not as a heritage restoration.

The nine-kilometre wall that did not save it

Odawara was the seat of the Hōjō, who held it for five generations and roughly a hundred years after Ise Sōzui (Hōjō Sōun) arrived around 1500. At its largest the defences were not a castle but a city: a sōgamae earthwork and moat about nine kilometres long that wrapped the castle and the town around it.

It was built against Toyotomi Hideyoshi, and in 1590 it failed. The siege ended the Hōjō, and with them the Sengoku period. That is the reason a small castle in Kanagawa keeps turning up in Japanese history: the war that unified the country finished here.

The castle that beat it is 1.9 km away

Hideyoshi did not batter Odawara down. He built his own castle in sight of it — Ishigakiyama Castle, remembered as the “overnight castle” — and waited. The two sites are 1.9 km apart in a straight line, and both are reached from the same station.

Almost nothing of Ishigakiyama survives except stonework on a hillside, so most visitors skip it. If you have read this far, it is the other half of the same story, and it is a short trip from the ticket gate you already walked through.

What was lost, and when

The castle was abolished in 1870 and most of its buildings were pulled down by 1872. The grounds became prefectural offices, and in 1901 an imperial villa was built in the second bailey. The Great Kantō Earthquake of September 1923 destroyed the villa and brought down almost all of the stone walls; the Edo-period appearance was gone.

What stands today went up piece by piece over seventy-five years: a corner turret in 1934, the keep in 1960, the Tokiwagi Gate in 1971, the Akagane Gate in 1997, and the Umadashi Gate in 2009. You are walking through a long reconstruction project, not a preserved castle.

The castle sets the height of the town

In 2006 Odawara City introduced a height limit for buildings based on the height of the keep, restricting construction above it so that the historic skyline is passed on. The rebuilt tower is not just a museum; it is the reference line the modern city is measured against.

From the top floor, roughly 60 m above sea level, you look out over Sagami Bay, and on a clear day as far as the Bōsō Peninsula.