Matsue Castle

Matsue Castle: The San'in Region's Only Surviving Keep

On the hill of Kameda-yama in central Matsue, Shimane Prefecture, stands a four-story castle keep that the Horio family completed in Keichō 16 (1611). It is the only surviving original castle keep in the entire San'in region of western Honshu, and one of just twelve such keeps remaining in Japan. In 2015, after two prayer tablets resurfaced and confirmed the year of its construction, the keep was designated a National Treasure, joining Himeji, Hikone, Matsumoto, and Inuyama in that select group.

The grounds themselves carry a separate national designation. The wider castle site, which preserves the Honmaru, Ninomaru, and Sannomaru baileys along with substantial stone walls and moats, has been a Historic Site since May 1934. Most visitors experience the two designations together: a walk up through the stone walls of the bailey, then up the steep wooden stairs inside the keep itself.

From Sekigahara to a Castle on the Lake

The story begins with the aftermath of the Battle of Sekigahara in 1600. Horio Tadauji, son of the veteran commander Horio Yoshiharu, was rewarded with 240,000 koku across Izumo and Oki provinces. The family initially took up residence at Gassan-Toda Castle in present-day Yasugi, a classic medieval mountain fortress no longer suited to running a domain or supporting a commercial castle town.

A move was requested, and in Keichō 12 (1607) construction began on a new site at the foot of Kameda-yama, near the channels linking Lake Shinji with Nakaumi. The work took five years. Tadauji died young during the planning, and the project passed to his son Tadaharu, with Yoshiharu acting as guardian. By early 1611 the keep was standing. Yoshiharu himself died that June, having seen his last great work nearly complete.

Some of the timbers in the lower stories did not come from new stock. They were carried from Gassan-Toda Castle and pressed back into service. Members carved with the character "富" (tomi), enclosed in the Horio family's bundō-mon (weight crest), can still be identified inside the keep, a literal carry-over from the family's earlier mountain stronghold.

The Prayer Tablets That Restored a National Treasure

Matsue's keep was designated a National Treasure once before, under the prewar Cultural Properties Preservation Law of 1929. When postwar legislation reset the categories in 1950, it was downgraded to an Important Cultural Property because the exact year of construction could not be documented from primary sources.

The piece of evidence needed to restore the top designation came from outside the building. In 1937, an architectural survey had noted the existence of two prayer tablets bearing the inscription "Keichō 16," and Matsue City spent decades searching for them. They were rediscovered in May 2012 during a survey of votive plaques at nearby Matsue Shrine. By matching the nail holes on the tablets to two through-pillars in the basement, researchers proved the tablets had once been fixed there as a dedicatory rite, performed in the first month of 1611 to consecrate the new structure. National Treasure designation followed on 8 July 2015, the first castle keep elevated to that status in sixty-three years.

Through-Pillars, Wrap-Boards, and a Well in the Basement

From outside, the keep reads as four roof tiers of black weatherboard above a rising stone base, with a small attached turret (tsuke-yagura) projecting from the south face to serve as the entrance. Inside, the count shifts to five floors over a basement. Specialists describe the form as bōrō-shiki: a watchtower set atop a substantial lower building, an older castle-keep type that fell out of fashion in the decades after Matsue was built.

The most distinctive structural choice is invisible from outside. Rather than running single timbers from base to crown (as Himeji Castle does), the Horio carpenters used through-pillars (tōshi-bashira) that span two floors at a time and alternate, so that the load passes from one set of pillars to another up the height of the building. A 1935 survey counted 308 columns in all, with thirty-eight through-pillars in just the lower two floors. Long timbers of sufficient straightness were in short supply during the post-Sekigahara castle-building rush, and this layered solution is generally read as a practical response to that scarcity.

Many of the columns are then wrapped. Thick boards (tsutsumi-ita) are clamped around the wooden core with iron staples and metal bands, reinforcing pillars that were not large enough on their own. The technique survives only at Matsue. The two columns in the basement that hold the rediscovered prayer tablets are the largest in the building and the only ones without wrap-boards, a measure of the spiritual weight assigned to them.

The basement holds another unusual feature: a well, sunk into the floor at the centre of the room. Castle keeps with internal wells were once known at Nagoya and Hamamatsu, but those wells are gone. Only Matsue's remains, originally 24 metres deep, now half filled in. The well speaks plainly to a building designed with siege in mind, regardless of how few sieges it actually saw.

Climbing to the Tengu Room

Visitors enter through the attached turret on the south side, climb past the well in the basement, and then ascend a series of steep wooden staircases that grow narrower as the building tapers. The lower floors hold exhibits on the construction, including a replica of one of the prayer tablets and a section of the original beam supports recovered from Gassan-Toda. Look for the diamond-set lattice windows, designed so muskets could fire through them at a wide angle, and for the narrow gun loops and arrow slits cut into the walls.

The top floor is the Tengu-no-ma, the "tengu room," open on all sides and ringed with a balustrade. From roughly thirty metres above the ground (some 60 metres above sea level, counting the hill), the view takes in Matsue's old streets, the modern town, the broad expanse of Lake Shinji to the west, and the mountains of the San'in spine to the south. Sunset over Shinji is widely held to be one of the finest in Japan, and the keep's western windows frame it well.

The Grounds and Castle Town

The keep alone takes perhaps thirty to forty-five minutes to climb and descend. The grounds, now Jōzan Park, deserve more. Within the Ninomaru sits the Kōunkaku, an ornate Western-style pavilion built in 1903 to receive the Crown Prince and now open to the public, alongside the small Matsue Shrine. The high stone walls of the Honmaru, built in the gobō-zumi and nozura-zumi techniques, are themselves worth slow inspection; some sections rise more than ten metres without mortar.

Encircling the whole is the original moat. A small fleet of low-roofed boats (the Horikawa Meguri) makes a fifty-minute loop along it, passing under seventeen bridges, four of which sit so low that the roof has to fold down for passage. The route slips along the Shiomi Nawate, a row of old samurai residences and earthen walls preserved much as Lafcadio Hearn (Koizumi Yakumo) would have known them when he lived nearby in the 1890s. His former residence and the museum dedicated to him stand within a short walk of the castle gate.