Gigantic private toy museum featuring among finest collections of antique mechanical banks in existence.

Friction between grains of sand cause a curious "singing" sound.

A collection of full-size movie monsters opened to the public.

The macabre graffiti spectacle in a quarry in a Massachusetts forest reservation.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

A Natural History and Science Emporium.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

Cliffs that hold fossils, including the earliest known reptile, dating back more than 300 million years.

A museum devoted to bringing to light forgotten or neglected histories through exhibitions, education and public programming.

A snapshot of the city's fascinating voodoo culture.

Introducing the Green Fairy to her fawning masses.

One man's lifelong obsession with death.

Arlington Cemetery exhibit dedicated to death and grieving.

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

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

An eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

Enormous lake at the bottom of a unique cave system.

Why have you never heard of the second most popular tourist site in New York?

Known for the tunnel that leads visitors to the water.

Once the path of a railway tunnel, now home to thousands of glowing insects.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

Tubing through a cave lit with glowworms is a magical underground experience.

Stalactites and stalagmites in a beautifully lit cave.