Ruins of a German Castle on top of a towering stone pillar.

A heavenly experience, right here on Terra Firma.

Once the most densely populated place in the world, this island is now a ghost town.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

Tokyo’s only Vaudeville-cuckoo clock–steampunk-Victorian curio cabinet time piece.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

Hollowed out cedar log tubs set in an ancient towering forest.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

This New Orleans tree is filled with hidden chimes that produce a carefully tuned melody.

360° views of the city plus five floors of optical illusions and hands-on science.

A museum befitting the city responsible for supplying the majority of the world's LSD.

Northern Ireland's Brobdingnagian stepping stones.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This volcanic cave lake is essentially hard proof that Iceland is the most magical place on Earth.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

A hospital closed seemingly in the middle of operations, leaving behind fodder for horror films and ghost hunters.

Crypt mausoleum in cathedral's basement contains relics of third century Roman martyr, Saint Vibiana.

A collection of oddities including Dr. Kevorkian's suicide device, the Thanatron.

Possibly the most beautiful carillon in the world, set atop Iron Mountain in Florida.

A rare view of a preserved Victorian science museum.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.