One of the world’s longest pedestrian suspension bridges.

An ancient underground cultic temple where sunlight penetrates on the summer solstice.

Built by a king and rebuilt by an emperor, this aqueduct transported water for 1,200 years to this ancient Mediterranean hub.

A roadway designed for a visiting monarch.

A failed infrastructure project now owns this unique moniker.

An early Korean refrigerator.

A giant repository of accidentally discovered cave paintings up to 30,000 years old.

A mountain cave is the site of archaeological findings and Paleolithic rock art.

These primitive rock paintings include a very beloved depiction of a woolly mammoth.

See replicas of Europe's most famous cave paintings and even some of the animals that feature in the art.

Fragments of human bones are embedded in the walls of this quaint alley.

Thanks to its heroic service during WWII this Soviet castle has been turned into a monument towered over by a brutalist titan.

This ancient amphitheater was restored in the early 1990s.

According to one local legend, this image was created during a battle between a wild lioness and the archangel Michael.

A forest of immensely tall and unusually straight oak trees planted nearly 200 years ago to build naval ships that never came to be.

The top of society once luxuriated in this world-class hotel, which continues to impress, even in ruin.

A once-luxurious, now abandoned hotel in the Italian Alps.

An abandoned resort in North Macedonia is a relic from the Communist Party of Yugoslavia.

The abandoned ruins of a failed resort hide on this verdant, picture-perfect island.

The now-overgrown beach resort was once frequented by Yugoslav military elite.

This abandoned five-star hotel is now a five-star urban exploration destination.

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

An abandoned Art Deco hotel nestled on the side of a wooded mountain.

An abandoned hotel in the highlands of Bali is shrouded in stories of ghosts, curses, and corruption.