Tunnel warfare

Japanese invasion of China (1937–1945)

line of fortifications along the French/German border

network of underground tunnels used by Viet Cong soldiers during combat

inactive Belgian fortress on the Belgian–Dutch border

architectural structure

warfare inside tunnels and other underground cavities

American, Australian, New Zealander, and South Vietnamese soldiers who performed underground search and destroy missions during the Vietnam War

use of tunnels for military operations in the Gaza Strip

one of four known tunnels located under the border between North Korea and South Korea

political killing in 1973 by ETA

fortress

2018 military operation

non-lethal bomb used to seal tunnels