This 12-seat movie theater is the smallest in the world.

This historic Victorian hotel has a scandalous history of affairs and murder.

Hidden within the waterfront hills resides this dilapidated military stronghold.

A larger-than-life version of the hat beloved by hunters, outdoorsmen, and Holden Caulfield.

The birthplace of the Ford Model T is now a museum full of antique cars.

The concrete shell of an industry giant remains as a playground for graffiti artists, auto scrappers, and paintball warriors.

One of Detroit’s oldest blues clubs stands in defiance of the passage of time and the city’s shifting fortunes.

This medieval castle was home to a known tyrant and features several hidden passages.

A visionary Italian architect created an impressive cluster of concrete structures for a family's private tomb.

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

An eclectic collection of highly specialized bicycles once used by artisans for their specific needs.

This work of engineering is imbued with elegance and ingeniousness.

Vast network of air raid tunnels beneath Lombardy's capital.

A larger-than-life house of cards stands outside the house of a former fashion designer.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.

Da Vinci's equestrian statue, 500 years in the making.

The mountaintop inspiration for Umberto Eco's "The Name of the Rose."

A complex, nine-layer maze on the grounds of a Venetian doge's playground.

Featuring the last fully walkable parapet walkway in Europe.

Destroyed numerous times, this centuries-old bridge has always been rebuilt with its original design.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

While most books are made of wood, these wooden books are truly made of, and all about wood.

Two bronze wolves atop this large rock honor the "Wolves of Tuscany" brigade of World War I.

Slovenia's first mosque is a striking mix of Islamic and modernist architecture.