A semi-scholarly approach to sex.

New York's oldest magic store.

Tucked in the back of this amazing antique store is an important piece of medical history.

A terrific purveyor of natural history objects and curios.

A crumbling hospital from the 1850s on Roosevelt Island.

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

This artificial cave looks like something out of a fairytale.

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

The first museum in the world devoted to sexual gadgetry.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Walk through Czech history in Prague's largest graveyard.

A Jenga-style cylindrical tower of books that appears to go on forever.

An abandoned quicksilver mining town surrounded by the Big Bend parks.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

A modernist landscape of water and sci-fi concrete.

Reportedly 1,400 years old, this may be the first of the Fiji Mermaids.

This former insane asylum now holds a pathological anatomy museum.

One of the oldest libraries in England, and one of the last of the great medieval chained collections.