This collection of French root art looks like an indoor fairy wonderland.

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

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

The highest peak in mainland Spain is said to be the final resting place of a Muslim king.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

The marble facade hides a little-known medical museum with early surgical instruments and rare copies of canonical texts.

A volcanic old faithful, Stromboli has been erupting continuously for the last 2000 years.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

This abandoned island off the Venetian coast has been a radical monastery, a political prison, and a secret Nazi base.

The plague quarantine island home to the alleged "Vampire of Venice."

Go inside to really appreciate this 500-year-old technological masterpiece.

Venice's "Island of the Mad."

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

The largest medical and anatomical collection in France lies hidden from the public.

Former hunting lodge of a duke who was an avid collector of impressionist works.

The Argonaute submarine was the French navy's pride and joy in the 1950's.

The recovered bones of martyrs slaughtered during The Terror are on display in this church crypt.

The historic Masonic Lodge in which the first-ever female Mason was initiated.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

Despite being considered a thoroughly American sport, basketball's oldest surviving playing field is found in the basement of a Paris YMCA.

An all-American grocery store in Paris sells U.S. "cuisine" like Pop-Tarts and Heinz ketchup to homesick ex-pats.

A magical, macabre wax museum, beloved by locals, uses real artifacts to depict an assassination from the French Revolution.

An odd museum dedicated to French fakes.