A uniquely lettered street sign marks the corner where the iconic word game was invented.

Empty, but not abandoned, this cavernous Brooklyn loading dock was once considered the largest individual building in the world.

A sculptural commentary on capitalism pokes up from the East River.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

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

It's a massive, rusted fountain that survived an earthquake in 1988.

A station imagined at the speed of light, where familiar fixtures slip out of place.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

The former headquarters of history's oldest megacorporation.

A floating cat sanctuary on an Amsterdam canal.

Widely advertised as Amsterdam’s narrowest street, this passage was once a highlight of the Red Light District before its windows closed.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

Europe's official "zero-level," the equator of elevation.

The smallest bar in Amsterdam has stayed in the family since 1798.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

This bird-loving brewery is situated in an old municipal bathhouse, nestled beside a 300-year-old windmill.

A unique seaside cave where Aleister Crowley faked his own death.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Hidden in one of New York's oldest subway stations is the final remnant of the site of the bizarre Shakespeare Riots.

An artist's cute bronze subway sculptures belie his violent artistic past.

Amid skyscrapers and traffic exists this unique aquatic ecosystem.