This is thanks to an engineering marvel known as the G-Cans, a colossal system of tunnels and reservoirs built beneath the ...

A second underground hollow space was discovered in Tokyo’s Chofu city that neighborhood residents strongly suspect is associated with underground tunnel work by an expressway operator ...

Underneath Tokyo’s bustling metropolis lies a maze of concrete tunnels built by Nippon Telegraph and Telephone Corporation to hold telephone and Internet cables. Photo: Alexander Martin/The Wall ...