A reverberatory furnace is a type of arched furnace that reflects heat and flame inside the chamber, allowing pig iron to be melted at temperatures exceeding 1,500 degrees Celsius. In Japan, such furnaces were introduced in the mid-19th century, primarily for the casting of iron cannons.

In the Satsuma Domain, research into reverberatory furnaces began in 1851, under the leadership of the 28th head of the Shimazu family, Shimazu Nariakira. The domain obtained a Dutch technical book titled Casting Methods at the Royal Cannon Foundry of Liège, written by the Dutch military engineer Huguenin. Using this text as their sole reference, the people of Satsuma undertook the construction on their own.

In 1852, the first furnace was completed on land adjacent to Sengan-en. However, problems soon appeared, including a leaning chimney, which made continued operation difficult. Learning from this failure, a second furnace was constructed in 1857.

The second furnace incorporated a number of innovations unique to Satsuma. The stone foundation supporting the chimney, approximately 20 meters high, was built using welded tuff stone, a local material. The stonework employed advanced castle-construction techniques so precise that it was said “not even a razor blade could pass between the stones.”

In addition, the production of fire-resistant bricks made use of the skills of Satsuma ware potters, resulting in a structure that combined Western scientific knowledge with traditional Japanese craftsmanship.

After the Anglo-Satsuma War of 1863, the reverberatory furnace was dismantled. However, the remaining stone foundation is an important physical record of Japan’s early industrialization.

For this reason, in 2015, the site was registered as a component of the UNESCO World Cultural Heritage, “Sites of Japan’s Meiji Industrial Revolution.”