岩柜真田忍者博物馆「忍博」，群马

The Iwabitsu Sanada Ninja Museum, commonly known as Ninpaku, is located in Higashi-Agatsuma, Gunma Prefecture, in the former Iwabitsu village area. The museum was established to preserve and showcase the history of the Sanada clan and their network of ninja operatives who operated in this region during the Sengoku period (16th century). The Sanada family, led by the legendary strategist Sanada Masayuki and his son Sanada Yukimura, controlled territories in present-day Gunma and Nagano prefectures.

The museum holds cultural significance as one of the few facilities in Japan dedicated specifically to authentic ninja history rather than entertainment portrayals. The collection includes historical documents, weapons, tools, and equipment actually used by ninja operatives in the Sanada clan's service. Exhibits explain espionage techniques, coded communication methods, survival skills, and the role of ninja in feudal warfare. The museum distinguishes between historical facts and popular myths surrounding ninja culture, providing scholarly context about these covert agents who functioned as scouts, spies, and unconventional warriors during Japan's warring states period.

Visitors can explore exhibition halls displaying ninja weapons including shuriken (throwing stars), kunai (multipurpose daggers), and concealed blades, along with specialized tools for infiltration and escape. Interactive demonstrations show how ninja used disguises, created smoke screens, and employed distraction techniques.

The museum features a trick house section where visitors navigate rooms with hidden doors, trap floors, and concealed passages designed to confuse intruders. Hands-on activities allow guests to practice shuriken throwing at designated targets under supervision. Educational displays cover the Sanada clan's military campaigns, including their defense of Ueda Castle against the Tokugawa forces.

Access the Iwabitsu Sanada Ninja Museum from JR Agatsuma Line's Iwabitsu Station, located approximately 15 minutes on foot from the museum. From Tokyo, take the JR Joetsu Shinkansen to Takasaki Station (about 1 hour), then transfer to the JR Agatsuma Line for roughly 1 hour to Iwabitsu Station. By car, use the Kanetsu Expressway and exit at Shibukawa-Ikaho Interchange, then drive approximately 40 minutes to the museum.