This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Rare recess caves fill this unbelievably beautiful Ohio park.

A World War II torpedo launch station abandoned off the Polish coast.

A spectacular hidden beach in Ireland has the dark, disturbing nickname of "Murder Hole Beach."

An unusual sand beach in the middle of a forest.

This natural wonderland is a unique chance to explore a Carolina bay, a mysterious geological formation of unknown origin.

This narrow canyon has been carved by the river over thousands of years into spectacular and curious forms.

Natural rock water slides hidden in the remote forests of northern Idaho.

A little-visited waterfall in an otherworldly landscape.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

A striking, menacing sandstone peak towering above a landscape that's equal parts Mordor and the Moon.

The largest copper mine in Arizona, this enormous open pit emerges from the hills like an alien landscape.

Rippling sand dunes frozen in the Arizona rock.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.

World's largest collection of serial killer artwork and other macabre exhibits.

An artsy hidden staircase leads to breathtaking views of San Francisco.

Modeled after the labyrinth in Chartres Cathedral, this small-town Indiana memorial labyrinth sits half a world away.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

A huge musical instrument played by the ocean.