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

Venice's island of the dead.

100 year tradition of fist fights, marked by marble footsteps.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

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

Venice's "Island of the Mad."

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

Originally a leper colony, the island is now an Armenian monastery that's home to an incredible manuscript library and eclectic museum.

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

South Carolina's last remaining slavery auction house is now a museum devoted to its own tragic history.

An art installation commemorates journalist Nellie Bly's undercover reporting inside a New York asylum.

An aptly-named street near the birthplace of the modern LGBT rights movement.

Enormous one time fiber mill now houses local artists and small businesses.

The longest continuous underwater road in North America was built at the insistence of Franklin Roosevelt.

As telephones become more essential and less stylish one historic Brooklyn building remembers the days when they were a grand celebration of communication.

This outdoor gallery of sculptures along the East River was once a landfill.

New York's southernmost subway station is whimsically wavy.

The façade of this building looks like a bingo board, but it's really a giant clock by a famed graphic designer.

A forgotten relic from New York's bygone trolley system hides in plain sight under a bridge.

Spike Lee's provocative film is officially honored right where it was made, the first time a work of art was used as a secondary street name.

There are owls with glowing eyes in Herald Square.