Under the streets of La Rochelle, a former wartime bunker holds some surprising secrets.

During World War II, locals rallied together to buy this plane to support the war effort.

Witness to Nazi occupation, this bunker has managed to soldier on to this day.

This cemetery contains a small fraction of the hundreds of Sierra Leoneans who died in the world wars.

This cone-shaped bomb shelter, modeled on German design, is a rare WWII relic that never saw use but still looms over the harbor.

At this concrete bunker on the Trondheim fjord, secrets lie above and below the water's surface.