Hokkaido University Wakayama Research Forest Main Building

A Hokkaido Building in the Mountains of Kii

The Main Building of the Hokkaido University Wakayama Research Forest (北海道大学和歌山研究林本館, Hokkaidō Daigaku Wakayama Kenkyūrin Honkan) is a two-storey timber building in the village of Hirai, Kozagawa Town, Wakayama Prefecture, completed in 1927 and listed as a Registered Tangible Cultural Property of Japan on 29 March 2013.

Hirai sits on the upper reaches of the Hirai River, a tributary of the Kozagawa, roughly midway between Shirahama and Shingū on the southern Kii Peninsula. The houses along the single road are single-storey and wooden. Then the ground rises slightly and a steep-pitched roof appears above them, painted metal over timber, symmetrical, with two gabled wings pushed forward and their end walls turned to face the road. It reads as a building from somewhere else, because it is.

The plan is H-shaped. Building area is 182 square metres. The exterior walls are clad in horizontal weatherboarding, except on the gable ends of the two wings, where shingle cladding is used instead. The original windows were double and triple sash units; these were later converted to sliding type. Inside the roof, the frame is a rafter structure with tie beams, a straightforward system that has held the building through a century of typhoons.

Why a Hokkaido University Owns a Forest in Wakayama

Hokkaido Imperial University, as it then was, needed a warm-temperate forest. Students training as foresters and forest scientists in Sapporo were learning in subarctic conditions, and the university wanted somewhere on Honshu where they could work in a different climate zone. In 1925 it went looking for land.

The approach was made through the national governors' conference, and Wakayama Prefecture volunteered. Four candidate sites within the prefecture were examined. Hirai was chosen because the holding had no detached parcels and because the local community pushed hard to be selected. The university bought part of a forest that the village of Hirai had held and managed in common.

Two years later, in 1927, the main building went up, framed with timber cut from the surrounding slopes. The design came from the maintenance and construction office of Hokkaido Imperial University in Sapporo, and the blueprints survive; the master carpenter was a builder from Hirai itself. It was planned as lodging for visiting students and staff, since teaching at the forest is done in the field.

The building carries details from the north that Hirai has no use for. The roof pitch is steep. The canopy above the entrance is braced with chains. The foundation stands high off the ground. These are answers to snow load, and it hardly snows in Hirai. The designers in Sapporo appear to have drawn what they knew, or to have wanted the Sapporo campus visible in the Kii mountains.

Inside, the two-storey front block held student sleeping rooms and workrooms; the single-storey rear block contained tatami rooms for teaching staff; the corridor linking them ran past the kitchen and washing facilities. Repairs in 1995 changed some of the room uses, but the fabric and atmosphere of 1927 remain largely intact. There is a small observation space up under the roof.

The Forest Around It

The research forest covers about 447 hectares, some 4.5 square kilometres, rising from around 240 metres at the entrance to the 842-metre summit of Mount Ōmori. The main building itself sits at about 190 metres. Seventy per cent of the terrain slopes at more than thirty degrees. The bedrock belongs to the Paleogene Muro Group, sandstone and interbedded sandstone and mudstone, and the soils above it are thin.

Rainfall here is extraordinary by Japanese standards. The 1991 to 2020 normal is about 3,500 millimetres a year, placing the area eleventh among the 1,022 AMeDAS observation points nationwide. Mean annual temperature runs around 15 degrees Celsius. June to September brings the rainy season and the typhoons.

About three quarters of the forest is planted cedar and cypress. The remaining quarter is natural forest dominated by evergreen broadleaves, chinquapin and oak, and within it some sixty hectares have gone roughly a century without major human disturbance and are managed as a preserve. Small pure stands of wild cedar, cypress and kōyamaki survive there. In 2010 the forest was designated a special area of a Wakayama prefectural natural park.

The institution changed its name in 2002, from Wakayama Regional Experimental Forest to Wakayama Research Forest, when it moved from being an appendage of the agriculture faculty to a university-wide facility open to ecology, environmental science, medicine, engineering and the humanities alike. It marked its centenary in 2025.

Visiting

The exterior can be seen at any time. The interior is open without reservation, and the forest asks that visitors come on weekdays between roughly 9:00 and 16:40, when staff are present; if someone is free, they will give a short guided walk through the building. There is no admission charge. The whole site, building and forest alike, is non-smoking.

Getting there takes planning. The nearest stations are JR Koza, Kushimoto and Susami, with Nanki Shirahama Airport further off, but pick-up from these points is arranged only for research and teaching visits, not for casual sightseers. Hirai has no convenience store or supermarket, only a few vending machines, so bring what you need from Kushimoto or another town on the coast.

Driving into the forest itself is not permitted except in vehicles authorised by the research forest, because the internal roads suffer rockfall and subsidence. Since April 2024 a landslide at Ōharabira has closed roughly 500 metres of the national road between the main building and the forest, with no reopening announced as of December 2025. The building is unaffected; access beyond it is not.

Staff make wooden goods from timber grown on the site, mostly on rainy days when field work stops. These are sold year-round at the main building, at the Ichimaiwa roadside station, and at the Hokkaido University shop in Sapporo. Groups wanting a forestry field class or a guided walk in the forest should contact the office at 0735-77-0321 well ahead; two months' notice is requested for weekend arrangements.