島根県立古代出雲歴史博物館

The Shimane Museum of Ancient Izumo, opened in 2007 adjacent to Izumo Taisha Grand Shrine, is the most important facility in Japan for understanding the origins of Japanese sword steel. Izumo Province (eastern Shimane Prefecture) has been the heartland of tatara steelmaking — the unique Japanese process that produces tamahagane, the raw material of Japanese swords — for well over a thousand years. The museum's tatara iron-making exhibition stands as the finest anywhere, explaining every step of the process from sand-iron harvesting to three-day smelting in a clay furnace (takadono) to the final classification of the steel into tamahagane, zuku, and kera. Visitors gain a fundamental understanding of why tamahagane is the only material that can produce a sword that is simultaneously hard, flexible, and razor-sharp. The museum also displays finds from the extraordinary Kōjindani archaeological site (1984), where 358 bronze swords were unearthed in a single deposit — more than all previously known Japanese bronze swords combined — providing a dramatic glimpse of Izumo as a center of weapon culture in the Yayoi period. Ancient Izumo mythology, including the legend of Susanoo's encounter with the eight-headed Yamata-no-Orochi and the origin of the Kusanagi-no-Tsurugi (one of Japan's Three Imperial Treasures), is also treated in depth, connecting sword culture to Japan's deepest spiritual roots. A visit to the neighboring Okuizumo region, home of the Japan Sword Preservation Society's active tatara furnace (Nittō-ho Tatara), completes the experience.