Akayama Underground Tunnels

The Akayama Underground Tunnels form a military shelter complex carved into the hillsides near Tateyama, with a section of about 250 meters open for visitors to explore. The passages contain chambers that once housed command centers and medical facilities, with original structures still visible.

The Japanese Navy started construction in the late 1930s as tensions with other nations grew, turning the site into a strategic defensive position. During World War II, the tunnels served as a command center and hospital, sheltering personnel throughout the conflict.

The tunnels reveal how people lived and worked underground during wartime, with visible remnants of daily life from that era. Walking through them helps visitors understand the reality of how communities adapted to crisis.

The passages have uneven ground and low ceilings in places, so comfortable footwear and a willingness to crouch are needed. The interior stays cool and damp year-round, so bringing a light jacket is a good idea.

Many original items from the 1940s remain in place throughout the tunnels, including equipment and furniture left behind. These objects offer a raw sense of what daily work and life looked like in these underground spaces during wartime.