Guide
The Nirayama Reflex Blast Furnace is an industrial monument that symbolizes the technological innovation of the late Edo period. A 'reflex furnace' is a facility designed to melt pig iron to produce high-quality iron. This site is significant as the only surviving structure of an actually operational blast furnace in Japan and is registered as a UNESCO World Heritage site. The structure, including the furnace body and chimney, reaches a height of approximately 15.7 meters, serving as a vital piece of evidence regarding Japan's technological capabilities during the late 19th century.
Following the arrival of Commodore Perry in 1853, construction was accelerated to strengthen the defense of Edo Bay. While the project was initially planned for a location near Shimoda, it was relocated to its current site in Izunokuni due to factors such as the movement of the Perry Expedition. The construction was led by the local magistrate, Hidari Ebara, with the subsequent processes managed by his son, Toshitomi. Based on Dutch technical documents, the facility adopted a dual-furnace structure where two melting furnaces are arranged perpendicularly. After its completion in 1857, it served as a Shogunate-run facility for casting Western-style cannons until 1864.
The primary focus is the structure of the surviving blast furnace itself. Visitors can observe the mechanism used to achieve high temperatures by reflecting heat against the dome-shaped ceiling, as well as the structure of the melting chambers. Archaeological excavations have also uncovered cannon molds, providing a glimpse into the industrial processes of the time. The surrounding area includes the remains of workshops and warehouses where craftsmen once worked, allowing visitors to visualize the scale of the industrial site during its operation.
The facility is open year-round, though closing times vary by season. From April to September, the site closes at 17:00, and from October to March, it closes at 16:30. Visiting in spring allows you to enjoy the historical ruins alongside the beautiful seasonal scenery. Bright daylight hours are ideal for observing the intricate details of the furnace structure, the height of the chimney, and the surrounding workshop ruins.
Through the surviving industrial remains, you can witness the process of how engineers in the late Edo period melted iron to cast cannons. The exhibits and physical structures provide a visual understanding of the advanced technical skills and the movement toward Japan's modernization. It is a unique opportunity to connect with the historical industrial systems within a serene natural landscape.
The area around the Nirayama Reflex Blast Furnace is dotted with other historical buildings and cultural heritage sites. Many sites reflecting Edo-period architectural styles and industrial history are located nearby, making it easy to incorporate this visit into a historical walking tour. The natural environment of Izunokuni provides a beautiful backdrop for exploring this historical context.
As the tour primarily involves walking outdoors and observing historical ruins, comfortable clothing and walking shoes are highly recommended. Please check local signage for specific payment or guidance details. To protect the precious historical remains, please refrain from entering restricted areas or touching the structures. We ask for your cooperation in respecting the site and other visitors.