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

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

In the early 1800s, surgery was also a show.

A museum dedicated to the strange and extravagant costumes and memorabilia of the mummers, a tradition older than Philadelphia itself.

The first American department store, and home to the largest operating musical instrument in the world.

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.

Dr Barnes' $25 billion private collection of art and arboretum.

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

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

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

Huge masonic hall in Philadelphia with lavishly themed rooms.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

World's first "penitentiary," meant to be humane, drove men insane.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

A rare view of a preserved Victorian science museum.

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

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

A temple to modernity, tucked away amid Barcelona's more well known museums.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

This Funeral Hearse Museum represents the finest in cadaver transportation.

A stately palace has been converted into the world's largest cannabis museum.