A collection of artworks exclusively created by the mentally ill that was almost burned by Nazi culture police.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The world's tallest church tower reveals a spectacular view to anyone up to the task of climbing the daunting staircase.

The prototype for all Nazi concentration camps.

Money made from smuggling sugar helped create this wondrous rock maze in honor of the Prussian Queen Louise.

This famed marionette theater and museum is bursting with imaginative string puppets.

Most often copied TV Tower in the world.

In this truly magical place, rent hasn't been raised since the year 1520.

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

This small chapel is built of human bones and decorated with a golden skeleton.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

One of the largest Roman settlements in Portugal.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

This ghost town in Belgium will lose its street art when it ceases to exist.

A phallic shrine to a princess goddess in Krabi, Thailand.

This wooden recreation of a 9th century lake village looks as though it was built yesterday (which it relatively was).

This impressively complicated radioastronomy research center was once a tool of Soviet spies.

The world's most active stratovolcano is almost always erupting.

This legendary city has been a tourist attraction for centuries.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.