One of the world's heaviest musical instruments towers within a popular urban park.

A giant red chair bolted to a rock on a remote mossy hillside in Iceland.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

A cablecar-station-turned-revolving restaurant with 360-degree views of the Swiss skyline.

A vintage penny arcade hidden in the back of a fun fair-themed bar.

Every Tuesday, students let off steam by screaming into the night air.

The secret wartime bunker built on the platforms of an abandoned Tube station.

Two dozen pinball games hidden away inside a most unlikely location.

An unusual collection of self-made musical instruments and unique noises.

Rare documents, old instruments, and gruesome specimens showcase the history of military medicine.

This street has over a half-dozen names, all at once.

The "beautiful" equation predicting the movement of all electromagnetic particles is engraved in front of Newton's tomb.

The site of many tense prisoner exchanges across the Military Demarcation Line between North and South Korea.

An eerie, little-known Neapolitan museum filled with preserved human remains.

A monument to the two U.S. officers killed by North Korean troops while trying to trim a poplar tree.

São Paulo's oldest magic shop has been hiding in plain sight for nearly four decades.

An exceptional assortment of fossils recovered from private collections.

This amazingly preserved Doric temple was abandoned before it was ever completed.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

These imposing walls and towers look more like the ruins of a fortress than a monastery.

Memorials at a Florence railway station remember the citizens who were deported from Italy and sent to extermination camps.

An ancient Egyptian temple sits within a modern European museum.

An ancient Viking runestone hidden in plain view in Stockholm's old town.