Though its celestial ceiling is impressive, the true star is the vast collection of French books.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

Volunteer-run library dedicated to exploring five decades of activism history.

A hands-on traveling collection of the innovative devices of yesteryear.

When ecosystems collide in the arid Southwest.

The highest bridge in America was built for an almost unnervingly small amount of money.

The largest self-built castle in the U.S., six decades in the making.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

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

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

This ancient structure is widely thought to be the oldest intact pyramid in the world.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

Known as the Sistine Chapel of Egypt, this tomb houses some of the most well-preserved paintings in Egypt.

One of the most well-preserved temples of ancient Egypt.

Ozymandias’ time-keeping temple.

A miniature train-ride through Slovenia's largest cave system.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

This one-time health resort was used by aristocrats around the world.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

A startling, centuries-old subterranean marvel hides in plain sight.

These steeply terraced ruins are a stop along the Inca Trail to Machu Picchu.

One of the world's tallest waterfalls wasn't revealed to the world at large until 2006.

This scalding hot river was thought to be a myth until one geoscientist made it his quest to study the mystical waters.

The ancient settlement attracts tourists from all over looking to learn about the Chinese vision of the afterlife.