This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

An eerie, derelict amusement park in Berlin.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

The world's only museum devoted to the wonders of fluorescence.

An enormous, inside-out glass globe built in 1935.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

Abandoned railway line circling the city of Paris.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

A psychedelic labyrinth on the San Francisco bay.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

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

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

New York's oldest magic store.

A snapshot of the city's fascinating voodoo culture.

These fantastically named natural pools look like something out of a Scottish myth.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

A kaleidoscopic warehouse-maze of handmade neon signs.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.