A wood-and-steel sculpture garden featuring an artful interplay of nature and machinery.

100-windowed castle turned art gallery, built by one dedicated mason.

Despite centuries of architectural innovation, this French castle is being built like it's the 13th century.

This otherworldly French waterfall looks like its waters have turned to stone.

The last Tsar of Russia constructed this private church just so he could attend services when visiting his wife's hometown.

A quaint medieval millhouse hovers surprisingly above the waters of the Seine.

This 18th-century folly is one of Europe's rare "garden mosques."

This stone amphitheater was once part of Nazi Germany's plan to promote propaganda.

Ivy-covered Medieval tunnels cut through this charming town in France's Loire Valley.

A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."

A mosaic-tiled house built by graveyard sweeper Raymond Isidore.

A public park off the beaten path with a beautiful waterfall and 13th century Cistercian abbey.

Where the high court feasted, frolicked, and high courtesans put their royal lovers' diamonds to the test.

The ruins of an abbey believed to have been founded by Charlemagne in the 9th century.

This breathtaking monastery was established by Saint Benedict himself 1,500 years ago.

An abandoned train station in Munich constructed for the 1972 Olympic games.

A subterranean shelter remains intact under a busy Paris railway station.

A 1,000-year-old church holds the bones of the Christian martyrs who died hiding inside it.

The highest waterfall in Italy is only "turned on" five times a year.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

The mystic whose incorrupt corpse still attracts the faithful.

Eighteen mummies have stood guard behind the altar of this tiny church since 1833.

A small man-controlled waterfall powers an Art Nouveau elevator and is accessed via narrow gauge, solar-powered tramway.

The abandoned mine where American troops discovered a treasure trove of art and artifacts hidden by the Nazis.