Inside this Krakow church, an explosion of psychedelic color.

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

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Real bones which are said to have belonged to a Polish dragon.

An underground city of salt.

Extremely famous in his native country, this Cracovian painter is all but unknown beyond Polish borders.

Down this Cracovian street resides a plaque with a stark message about the city's air pollution.

Learn the fine art of making a centuries-old treat at this hands-on food museum.

This memorial honors thousands of enslaved Africans and their descendants who died in colonial New York.

Imagine having a street run right through your home, or better yet, a historic bridge three stories high.

The former hotel where Tesla invented the radio.

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

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

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

“Invented in Key West, Perfected in Brooklyn."

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

Ride the subways of yesteryear.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

NYC's legendary underground network for bovine transportation.

An homage to Jackie Gleason's bus-driving character from 'The Honeymooners.'

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

The home of one of America's most beloved fictional characters has become a real world landmark.