A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.

A rare example of an octagonal Catholic church.

All that is left of this medieval castle is two towers, both of which now display a visible tilt.

This Renaissance palace features a unique architectural design and is now home to the Ferrara National Art Gallery.

Much of what constituted mid-century Liverpool now litters a beach outside of town.

In France, a medieval-style home pays homage to an intrepid explorer who discovered Québec.

This tiny hotel perched atop a 50-foot tower really puts things into perspective.

This small island, a byproduct of 19th-century canal construction, is now home to a charming Japanese garden.

The unexpectedly beloved remnants of a controversial thermal power plant.

A small museum in Newfoundland is home to a 227-foot tapestry that preserves the remote region's colorful history.

The former atelier of Mario Cassisa is a treasure trove of paintings, sculptures, and artist books.

A temple to modernity, tucked away amid Barcelona's more well known museums.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

This granite rock face is named for the magnificent reflection that occurs when the sun hits it just right.

Since 1887, this old-school shop has stacked its shelves with extraordinary coffees and teas.

Ottoman-era houses lovingly preserved.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

A Turkish ghost town abandoned in a population exchange with Greece.

This famous city eluded concrete detection until the early 2000's.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

A secret door leads to this cozy dive that sells only “milk.”