Former Hadeba Hydroelectric Power Station: A Cathedral of Industry in the Mountains of Ehime

Deep in the forested mountains of Niihama City, Ehime Prefecture, a magnificent red-brick building stands on a steep hillside overlooking the Ashitani River valley. This is the Former Hadeba Hydroelectric Power Station (旧端出場水力発電所, Kyū Hadeba Suiryoku Hatsudensho) — a masterpiece of Meiji-era industrial architecture that powered one of Japan's most important copper mines for nearly six decades. With its elegant arched windows, sturdy English-bond brickwork, and cathedral-like interior housing century-old German generators, this remarkable structure offers visitors a rare and unforgettable encounter with Japan's industrial heritage.

A Brief History: Powering the Besshi Copper Mine

The Besshi Copper Mine, discovered in 1690 in the Akaishi Mountains of Shikoku, operated for an extraordinary 283 years and was the second-largest copper source in Japanese history. By the late Meiji period, the mine's growing operations demanded far more electricity than existing facilities could provide. The Hadeba Hydroelectric Power Station was constructed to meet this urgent need, entering service in 1912 (Meiji 45).

The power station was an engineering marvel of its time. Water was drawn from the Dōzangawa River, a tributary of the Yoshino River system on the southern side of the mountain divide, channeled through mining tunnels including the Hiura Adit and the Third Adit, and collected in a brick-built water tank at Ishigayamajō at an elevation of approximately 750 meters. From there, water plunged through steel pressure pipes with an effective drop of 597 meters — the greatest in the Orient at that time — to drive the turbines below.

At its inauguration, the station produced 3,000 kW, making it one of the largest hydroelectric facilities in Japan. Capacity was later expanded to a maximum of 4,800 kW. The electricity it generated powered not only the mine's underground railways and machinery but was also transmitted via a 20-kilometer submarine cable — then the longest in the world — to the Shisakajima Smelter on an island in the Seto Inland Sea. This pioneering long-distance submarine power transmission made significant contributions to the development of undersea cable technology worldwide.

The station continued operating until 1970 (Showa 45), when it was decommissioned after 59 years of faithful service. In 2010, Sumitomo Joint Electric Power Co. donated the facility to Niihama City, and in 2011 it was designated a Registered Tangible Cultural Property of Japan. Following extensive seismic reinforcement work that began in 2018, the station reopened for public viewing in March 2023.

Why It Was Designated a Cultural Property

The Former Hadeba Hydroelectric Power Station received its designation as a Registered Tangible Cultural Property (登録有形文化財) in January 2011 for several compelling reasons:

The building itself is an outstanding example of early 20th-century industrial architecture. It is a two-story brick structure with a building area of 528 square meters, roofed with iron sheeting and equipped with two clerestory ventilators. The brickwork employs the English bond technique, with pilaster strips on the side elevations supporting paired arched windows above and large segmental arch openings below. The contrast between the warm red brick and strategically placed stone accents creates a strikingly handsome façade that harmonizes beautifully with the surrounding deep-green mountainside.

Beyond its architectural distinction, the station is also recognized as part of the Besshi Copper Mine Industrial Heritage Group, designated by Japan's Ministry of Economy, Trade and Industry as a Heritage of Industrial Modernization. The facility embodies the technological ambitions of Meiji-era Japan and demonstrates how the nation adapted Western engineering to its mountainous landscape with remarkable ingenuity.

Highlights and What to See

Visiting Tips

The power station is located adjacent to Minetopia Besshi, a popular mining-themed park built on the former Besshi Copper Mine site. To reach the power station, visitors should park at Minetopia Besshi's free parking area and walk upstream along the Kuniigawa River to the Ashitani Bridge, then cross over and follow the pedestrian path along the prefectural road. The walk takes approximately 10 to 15 minutes and includes stairs with a height difference of about 10 meters, so comfortable walking shoes are recommended.

Please note that there are no restroom facilities inside the power station — visitors should use the restrooms at Minetopia Besshi before making the walk. Food, drink, and smoking are not permitted inside the building.

Spring and autumn are particularly beautiful times to visit, when cherry blossoms or autumn foliage frame the red-brick building against the mountain backdrop. Multilingual information is available through online resources accessible via QR codes at the site.

Surrounding Attractions

A visit to the Former Hadeba Hydroelectric Power Station can easily be combined with exploration of the broader Besshi Copper Mine heritage area:

• Minetopia Besshi (Hadeba Zone): Ride a replica mining train, try gold panning, visit the educational mine tunnel, and relax at Besshi Onsen Tenku no Yu hot springs.
• Tonaru Zone (Oriental Machu Picchu): Located further up the mountain at 750 meters elevation, the dramatic stone ruins of the former mining town have earned the nickname "Machu Picchu of the Orient."
• Besshi Copper Mine Memorial Museum: Learn about 283 years of mining history through exhibits, dioramas, and historic photographs.
• Hirose Saihei Memorial Museum: Discover the life of the visionary manager who modernized the Besshi operations and laid the foundations of the Sumitomo Group.
• Former Yamane Smelter Chimney: A 20-meter brick chimney, the oldest heritage of heavy chemical industry in Japan, offering panoramic views of Niihama and the Seto Inland Sea.