This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

The only museum with its curator—and her pets—buried inside.

The great Italian Renaissance painter was laid to rest here in the Chapel of Saint-Hubert.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

The opulent home that inspired Tintin's Marlinspike Hall and the adventures within.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.

A beautiful and classically designed villa, with an hourly infestation of monsters.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

Specimens collected by the author of "Lolita" and self-taught lepidopterist are exhibited in his childhood home.

A sudden, striking cluster of hills south of Padua has been attracting visitors for centuries.

The world's oldest surviving anatomical theater, where "the dead are pleased to help the living."

The oldest botanical garden in the world that technically isn't the oldest.

The oldest inn in England served brew to the crusaders.

When the public was consulted about a new piece of street art, they naturally asked for an enormous metal dragon.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

This enchanting hamlet carved into the rock looks like something straight out of Tolkien's Rivendell.

A floating underwater hotel, created by a Swedish artist.

A unique Tuscan hideaway acts as an art mecca as well as a hotel.

This 16th-century monastery has been turned into a surrealist architecture compound.

Hidden in an Italian forest is a completely homemade amusement park that has taken a lifetime to create.

Perhaps the tiniest sculpture in Saint Petersburg is a little bronze finch inspired by a song.

An army of sleeping knights sculpted by a self-taught local artist beautifully depict an old Czech legend.

The yawning maw of this pagan visage is said to bite off the hands of liars.