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.

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

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

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

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

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

A miniature rainforest is growing inside of a Midtown Manhattan office building.

A beautiful, dense forest in the shadow of Mount Fuji, with a tragic reputation.

A church of bones, decorated with 40,000 human skeletons.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

The sign at the garden gate reads: "These Plants Can Kill."

Hot springs monkey spa in the middle of Hell's Valley.

Medicinal spa created with the discharge from a geothermal energy plant.

Dramatic river bend surrounds a natural red-rocked pedestal.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

The world's only museum devoted to the wonders of fluorescence.

These fantastically named natural pools look like something out of a Scottish myth.