This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

A floating cat sanctuary on an Amsterdam canal.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

Southern Italy's spinning top village.

This precariously perched fortress was once ruled by a crow-worshipping baron.

This mountain trail inspired Nietzsche to complete his magnum opus.

This massive blockhead sculpture hides an entire library.

A medieval military street hidden beneath a charming French fishing village.

This ancient theater was once the home of fierce gladiatorial battles.

A unique underground structure dating back to the 1st century BC.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

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

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Overlooking the Colorado Convention Center is this giant sculpture made from thousands of triangles.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

An off-grid art installation that encourages its visitors to imagine a world without waste.

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

A hand-built folk art installation covered with messages of God's love.

Version of the French Riviera destroyed by the sea.

The ghostly remains of an accidental sea.

A fake town founded by Western movie stars is now becoming a hip desert community.