Several 12th-century ruins can be found inside this historical market.

The iconic Manhattan corner that was once the site of the Beastie Boys' fake clothing store.

Salute the leader of the proletariat.

A hidden "place of interment for gentlemen."

Spiral-bound community recipes and antiquarian gems mingle at this small East Village shop.

The one-time epicenter of American songwriting is now a little remembered Manhattan commercial block.

Avoid gangster interaction while window-shopping.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

A giant Troll lurks under one of Seattle's oldest bridges.

The longest of the four remaining covered bridges in Missouri.

Venice's island of the dead.

The only museum with its curator—and her pets—buried inside.

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

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

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

Baroque celebration of the end of the Great Plague of Vienna.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

A 70-foot replica of the famed Eiffel Tower.

A tribute to Ponce de Leon's supposed quest for eternal youth.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

St. Augustine's record-setting narrow street was designed to protect against pirates.

In this case, 'zero' marks the spot where the iconic Old Spanish Trail ends.