Go surfing on this urban wave, "hacked" by local surfers.

A beautiful gorge filled with streams and waterfalls.

This statue of the legendary Austrian composer is hidden in the center of an Italian town.

One of the most well-preserved castles in Italy also contains a rare medieval example of a port fortification.

Pilgrimage site for star-crossed lovers.

The world's largest reflecting pool is just two centimeters deep.

This Bordeaux parking garage has 712 indoor spaces, and one outdoor.

Abandoned blockhouses from Nazi Germany's Atlantic Wall erode into the sea on a French beach.

This medieval chapel is now a shrine to the region's favorite sport.

Beneath the city of Lourdes, France is a massive, concrete church.

This narrow path was cut right into a French mountainside to feed the country's early naval expansion.

A young Gustave Eiffel assisted in the construction of this skinny metal observation tower.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

An underground city of salt.

There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

Look closely and you’ll notice that the color changes a third of the way up the tower.

A futuristic, brutalist masterpiece that is also strangely prison-like.

An unfinished Serbian Orthodox church with 1,389 golden crosses planned to represent the Battle of Kosovo.

The hidden ruins of an old hydroelectric plant reclaimed by nature.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

This unique architectural wonder is home to luxury apartments.

These enormous, stern-faced statues greet visitors with lanterns, and sometimes costumes.

This celebration of Latvia’s freedom and independence avoided demolition over half a century of Soviet occupation.