Warlords, Missionaries
& a Song That Never Ends

Edo period

✦ AI-generated illustration — not a photograph of the actual site

Capital of the Ōtomo clan's domain — the most powerful warlords in Kyushu — and home to Japan's first Western-style hospital and university

Funai was the capital of the Ōtomo clan at the height of their power, when they controlled two-thirds of Kyushu and styled themselves "Lords of Seven Provinces." Francis Xavier visited here in 1551. Ōtomo Sōrin built Japan's first Western-style hospital and university within the castle town with Jesuit assistance, making Funai briefly one of the most internationally connected cities in Japan. The castle itself was built by successive warlords after Sōrin's clan fell — two original turrets from the early 1600s still stand today, making them among the oldest surviving castle structures in Kyushu. The site is now a park famous for cherry blossoms, with dramatic nighttime light projections that restore the castle's appearance digitally on the ruins.

Edo period

✦ AI-generated illustration — not a photograph of the actual site

Considered by many to be the most beautiful castle ruins in Japan; inspired Japan's most famous classical song

Oka Castle does not have a surviving keep. It has something better: one kilometer of dramatic stone walls running along a mountain ridge 325 meters above sea level, with cliffs dropping on both sides into deep river gorges. The walls turn pink in spring with cherry blossoms, gold in autumn, and white in winter — and at any season, the views over Taketa's mountain-ringed valley feel impossibly cinematic. The ruins inspired composer Rentarō Taki to write "Kōjō no Tsuki" (The Moon over the Ruined Castle) in 1901 — a song so embedded in Japanese culture that it plays at train stations across the country. A bronze statue of Taki now stands at the castle entrance. Oka Castle is consistently rated by castle enthusiasts as the best castle ruins in all of Japan.

Edo period

✦ AI-generated illustration — not a photograph of the actual site

One of Japan's three great "water castles"; designed by the strategist who guided Toyotomi Hideyoshi's unification of Japan; birthplace of the man who put Japan's modernization on its ¥10,000 note

Nakatsu Castle has one of the most layered backstories of any castle in Kyushu. It was designed by Kuroda Yoshitaka — known as Kanbei — the military genius who planned Toyotomi Hideyoshi's campaigns and is considered one of the greatest strategists of the Sengoku era. He chose this site precisely for its water: the castle is surrounded by the Yamakuni River on one side and the Seto Inland Sea on another, making it one of Japan's three great "water castles." Its walls are famously built in two distinct styles — the lower stones laid by the Kuroda clan and the upper stones by the Hosokawa who followed — the join between them visible to this day. Near the castle, Fukuzawa Yukichi — the intellectual reformer whose face still appears on the ¥10,000 note — was born and educated. His childhood home is open to visitors.

Edo period

✦ AI-generated illustration — not a photograph of the actual site

Personal castle of Ōtomo Sōrin, the Christian warlord who sent Japan's first mission to the Pope; near Japan's only National Treasure stone Buddhas

Usuki Castle was Ōtomo Sōrin's personal stronghold — the place he retreated to after leaving his son in charge of the main Funai Castle. Its location is extraordinary: built atop a small island (Nyūjima) connected to the mainland only by a sandbar at low tide, surrounded on all sides by vertical cliffs. When the Shimazu clan attacked in 1586, Sōrin held out here using — for the first time in Japanese castle history — cannon fire in defense. The Shimazu eventually drove him out, but the castle's use of Western firearms was a milestone. Today only stone walls remain, surrounded by nearly 1,000 cherry trees. The nearby Usuki Stone Buddhas — Japan's only stone Buddhas designated National Treasures, carved into cliffs in the Heian period — make Usuki an unmissable detour from Beppu.