Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

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

This peculiar lake of pitch is so thick and viscous that one can walk on its surface.

In a long-dry lake bed, these groups of massive stone pillars bear a striking resemblance to clumps of everyone's favorite fungi.

This extraordinary geological oddity resembles human-made pavement.

A stunning silver lining to global warming's gloomy cloud.

137 graves holding New England's earliest residents.

A religious-themed park filled with folk art to bring biblical stories to life that fell into disrepair and now being restored.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

The "possessed" house that inspired "The Haunting in Connecticut" book and movie.

Started as a kitchen garden, now the second largest botanical garden in the world.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

Intensely colorful calcite pools in Southern China.

Have fun at the world's first Buddhist waterslide park.

Founded as a refugee camp, now a popular tourist spot.

An ethereal glowing blue ocean cave in Croatia.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

A beautiful geyser under environmental threat.

Roman ruins top white travertine terraces formed by ancient hot springs.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

Upside-down trees serve as natural flower pots in this hanging garden of Alaska.

Mysterious Spanish catacombs of unknown origins.

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

A naturally mummified 2,000-year-old man.