Three hundred years of preserved Spanish colonial history in San Antonio.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

The world’s first penitentiary, meant to be humane, drove men insane.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

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

Two stone columns flank the grand Venice square, but there were supposed to be three.

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

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

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

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

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.

Hundreds of antique bank vault locks on display in New York City.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

The celebrated eyesore created by starry-eyed sweethearts.

The curious underground history of keeping Paris clean.