Cliffside houses provide a spectacular view from their perch above the valley.

A neolithic tomb converted into a tiny chapel.

Pagan monument converted to Christianity with the population.

A landscape decorated with enormous skull sculptures.

Commonly acknowledged as the only public monument to the Devil himself.

The last woman executed for witchcraft in Europe is remembered in this Swiss museum.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

One of the few remaining American elm trees in New York’s Tompkins Square Park was the birthplace of a new religion.

In 1830, cemetery workers in Cham unearthed a chamber housing thousands of skeletal remains from the 13th century, which can still be viewed today.

The mystery of the Putim Ossuary involves a tricorn hat.

Legends of time travel and magical woodland creatures bolster the natural charm of this verdant sanctuary in the midst of Moscow.

A curious art park at the geographic center of Europe is home to 3,000 television sets and other wonders.

A Spanish forest is filled with mysterious stone carvings.

Planned as the world’s first zero-carbon city, it had lofty ideals—but is only 5 percent completed and aiming for 50 percent carbon-neutral.

The ceiling of Prohodna Cave in northern Bulgaria affords a peek at the sky via two deity-sized-eye-shaped holes.

This overgrown Illinois water park offers a whole new type of adventure.

After an epic flood washed away its enslavers, this city has been part ghost town, part cultural wildcard for the past three centuries.

Beneath a Virginia City bar is the entrance to an abandoned gold mine.

An Argentinian businessman facing terminal cancer built this whimsical medieval village using salvaged materials.

One man's little-known private clock museum hides inside a historic farmhouse, set amidst the Austrian countryside.

Long the exclusive domain of birds and vagabonds, this little-known Central Park peninsula is open to the public once more.

One man’s passion for gas stations is on display along the Rio Grande in northern New Mexico.

Where better to stay the night than inside a trio of ancient Chinese deities representing "the good life."

These Roman ruins in England’s Lake District are 2,000 years old, but look pretty good for their age.