A Romanesque tower appears when water levels drop.

The Mexican painter Diego Rivera created this unusual museum to display his collection of pre-Hispanic artifacts.

An otherworldly alpine pasture with its own unique microculture that recalls Middle Earth.

This magnificent market stands as a poignant symbol of the suffering caused by the Spanish Civil War.

New York's southernmost subway station is whimsically wavy.

Several of these strange cone-shaped bunkers can still be seen around the former Nazi headquarters.

A vibrant street away from the typical tourist track, lined with colorful, mosaic-covered houses.

The oldest funicular in Lithuania has been climbing this steep hill since 1931.

The luxurious circular mansion built for a Communist leader now lies abandoned.

A replica of the straw hut where Vladimir Lenin lived in hiding, disguised as a hay farmer, in 1917.

An unusual collection of self-made musical instruments and unique noises.

An abandoned 14th-century castle and prison complex on a small island in the Neva River.

A site where “the ravages of the war are more striking…than any other place in contemporary Spain.”

The world’s largest collection of Tiffany glass sits in a warehouse in Queens.

A statue of a boy looks up at where the famous rival to the Leaning Tower of Pisa once stood.

The world's largest solar furnace uses 10,000 mirrors to concentrate the sun's rays to generate power.

These striking ruins of a castle resemble a ship's stern.

The abandoned ruins of a beautiful medieval castle just outside Barcelona.

Military and first responders can test their skills in a Foggy Bottom mock station down in Georgia.

A Milanese café entirely designed by the American director Wes Anderson.

Relive a Polish uprising via an enormous, century-old cyclorama.

A collection of old neon signs from all over Poland line a secluded courtyard.

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.