An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This chimerical bridge/tunnel appears to dead end right into the sea.

Rebuilt remains of a temple to Roman god Mithras.

A museum dedicated to the history and exploration of both popular music and science fiction.

Visit the home of Sweden's beloved fictional character, Pippi Longstocking.

This demon atop the Notre-Dame de Paris looks utterly bored.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

An ancient Egyptian temple in the middle of Madrid, Spain.

The celebrated eyesore created by starry-eyed sweethearts.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

Across the Pacific in a raft, a museum dedicated to Thor Heyerdahl's now legendary expedition.

A collection of noses tucked inside an art museum reveals how times have changed.

The final resting place of the author who gave us the Little Mermaid, the Ugly Duckling, and many more beloved fairy tales.

The only surviving piece of Copenhagen's 16th-century defensive wall.

The largest of Denmark's seven mysterious round churches stands on an island in the Baltic Sea.

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.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

A private selection of curiosities, carefully curated by a young Brighton local.

The rotting skeleton of a shoreside fun fair that was destroyed by fire and storms still haunts the Brighton ocean view.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.