Zozan Imperial Wartime Tunnels

Zozan Imperial Wartime Tunnels

Officially known as the ‘Matsushiro Daihonei’ or  ‘Matsushiro Underground Imperial Headquarters’, the Zozan Tunnels are a series of extensive subterranean passageways, bunkers and living areas excavated beneath the quiet and unassuming town, in the final months of WWII.


Expecting invasion by the Allied Forces, the tunnels were intended to serve as the underground headquarters of the Japanese military and government. Construction of the tunnels required the labour of an workforce estimated to have numbered around 10,000, mostly forced Korean labourers.


A 500 metre section of the tunnels can still be entered today. Outside of the tunnel, a small museum commemorates the sacrifice and conditions endured by those tasked with constructing the tunnels. When visiting, please follow the rules and be conscious of the sensitivity of the site for many people.


09:00 to 17:00 (last entry at 16:30)

Open daily


Approximately a 50 to 70-minute drive from the Jigokudani Monkey Park

From Nagano Station, take the Alpico Bus bound for Matsushiro from Bus Stop No.3 - outside the station's Zenkoji Exit - and disembark at the Matsushiro Station Bus Stop - it takes between 30 to 35 minutes. Once in Matsushiro, the tunnels can be reached on foot in around 20 minutes from the bus stop. It will be easiest to first go by the Tourist Information Center to collect a map or rent a bicycle. From the bus stop tourist Information can be reached in around 5 minutes by taking either road to your left and then turning right when you reach the next road. Walk straight along that road until you see Tourist Information on your left, next to the Sanada Treasures Museum