It's always summer at the beach inside this former airship hangar.

The prototype for all Nazi concentration camps.

The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

An unfinished complex built for children from around the world sits abandoned on the Black Sea coastline.

An abandoned saucer-shaped monument in the Bulgarian mountains.

An amusement park on the grounds of an unused nuclear power plant, with a swing ride inside the cooling tower.

This massive steel pyramid can be entered by a set of jagged steps that let visitors stand in its heart.

No need to strap in for a "ride" on this walkable roller coaster.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.