The Building at the Centre of the Island, Now a Museum

At the middle of Nagashima, where the paths of the sanatorium converge, stands a reinforced-concrete building with a rounded porch and a heavy parapet. Finished in 1930 as the administration headquarters of Nagashima Aiseien, it was the first national sanatorium in Japan for people with Hansen's disease. The main block rises two storeys, with a single-storey section and a later wooden wing on the west; together they cover about 371 square metres. Since 2003 the building has held the Nagashima Aiseien History Museum.

For most of the twentieth century, Japanese law confined people diagnosed with Hansen's disease to sanatoriums for life. Decisions that shaped those lives, admissions, labour assignments, correspondence, were made inside this building. Its survival, and its conversion into a museum, turn the former nerve centre of the institution into a place where that history is now explained openly.

An Unexpected Piece of Modern Architecture

The administration building was registered as a Tangible Cultural Property in March 2019, listed under the criterion for design that sets a standard for its kind. What earns it that recognition is its architectural language. The rounded-arch opening of the south porte-cochere, the upper-floor windows and the broad parapet show the influence of Expressionism, a current in early-twentieth-century design rarely seen in a remote medical institution.

Concrete itself made a statement here. The choice to build the headquarters in reinforced concrete, at a time when most rural buildings were timber, reflects the fact that Aiseien was a direct project of the Home Ministry and meant to look the part. The west wing, added in timber, and later repairs in 1998 and 2003 are visible layers in the building's history rather than attempts to disguise its age.

Inside the History Museum

The museum separates two kinds of display: one explaining the policy of isolation and the events at Aiseien, the other devoted to the feelings and creative work of the people who lived here. A first screening room shows film material, and galleries present residents' pottery and other works. The former director's office, once described as the command post of isolation policy, has been recreated.

Of the five registered buildings featured in this series, this is the one visitors actually enter, and the right place to begin. Staff arrange guided walks that continue to the reception building by the wharf, the bathhouse and the laundry. Reservations are required, and the island remains home to residents, so visits are made on set terms and with care.

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Questions and Answers

QIs the History Museum open to the public?
AYes, by reservation. The museum occupies the former administration building and presents the history of Hansen's disease policy and life at Aiseien. Hours are roughly 9:30 to 16:00, with closures in summer and over the new year period. Confirm dates and book ahead before travelling.
QWhat is Expressionist architecture, in plain terms?
AIt is an early-twentieth-century style that favoured bold, sculptural forms over plain symmetry. Here it appears in the rounded arch of the entrance porch, the shaping of the windows and the thick parapet along the roofline.
QWhy was the headquarters built in concrete?
AAiseien was a flagship project run directly by the Home Ministry, so it was built to be durable and visible. Reinforced concrete was a deliberate, costly choice for a building meant to represent the new national institution.
QCan I see the original director's office?
AA recreation of the director's office is part of the museum display. It reflects the room's historical role as the centre from which isolation policy was directed.
QHow do I get there?
ANagashima is joined to the mainland by the Oku-Nagashima Bridge of 1988, called the Bridge of Human Restoration. By car it is about ten minutes from the Mushiake interchange on the Okayama Blue Line; buses run from Oku Station on the JR Ako Line. The museum also organises tour buses and boat visits on certain days.

Basic Information

NameFormer Administration Building, Nagashima Aiseien (Nagashima Aiseien Kyu-Jimu-Honkan); now the Nagashima Aiseien History Museum
Location6539 Mushiake, Oku-cho, Setouchi City, Okayama Prefecture
DesignationRegistered Tangible Cultural Property (Buildings)
Registration date29 March 2019
Registration number33-312
StructureReinforced concrete, two storeys with a partial single storey, plus a single-storey wooden wing; building area about 371 square metres
Year1930, with an early-Showa addition and repairs in 1998 and 2003
Quantity1 building
OwnerNational Sanatorium Nagashima Aiseien
Access and viewingOpen as the History Museum by reservation; via the Oku-Nagashima Bridge

References

Database of National Cultural Properties, Agency for Cultural Affairs: Nagashima Aiseien Former Administration Building
https://kunishitei.bunka.go.jp/bsys/maindetails/101/00012811
Cultural Heritage Online: Nagashima Aiseien Former Administration Building
https://bunka.nii.ac.jp/heritages/detail/379604
Nagashima Aiseien History Museum
https://www.aisei-rekishikan.jp/
Nagashima Aiseien, Leprosy.jp (Sasakawa Health Foundation)
https://leprosy.jp/japan/sanatoriums/sanatorium07/

Last verified: 2026.06.25