This head-spinningly bizarre Depression-era art cave is wall-to-wall quartz and Jesus.

More than five miles of underground passageways.

This replica of the Greek structure is in the heart of Nashville.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

The Master of Magnetism dominates the walls of a scrap metal yard to keep graffiti artists at bay.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

Found art has transformed this Pittsburgh neighborhood into a psychedelic dream.

House of vintage taxidermy and Steampunk sculptures in a quiet Pittsburgh neighborhood.

This beloved marketplace mascot poops money and grants good luck.

South Philadelphia is home to Keith Haring's only surviving in situ collaborative public mural.

This Philly landmark has a giant butterfly pavilion, three floors of insect displays, and withstood a $40,000 heist.

This little-known Revolutionary War fort is supposedly haunted by the ghosts of its past.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

One artist's love letter to his city and its citizens plays out across dozens of bright murals painted on the sides of decrepit buildings.

The taxidermied remains of Charles Dickens' pet raven, which helped inspire one of Edgar Allan Poe's most famous poems.

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

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

A layered tribute to the work of mosaicist Isaiah Zagar.

The first custom-designed building to showcase the works of Dale Chihuly is a wonderland of glass and light.

The oldest operating Mississippi River–style steamboat still navigates the Ohio River.

The Midwestern United States' tribute to Michelangelo is a foam statue sprayed with gaudy gold paint.

This alley in downtown Chicago held the bodies of over 600 people after the fateful Iroquois Theatre fire.