A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

Descend 2,030 years into the past in an ancient tunnel built to support Jerusalem's most famous wall.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

Fascinating town where normal life interfaces with the occult.

This religious complex carved into a cliff is steeped in legends of miraculous stags and the Holy Grail.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

Lured here by the promise of tens of thousands in gold, Jesse James started a quintessentially American trend of robbing trains in-motion.

A quaint village in Western New York named after Alexander Hamilton's beloved sister-in-law.

This glamorous old building is said to have inspired the Tower of Terror.

A beautifully well-preserved ancient Roman villa.

Just outside of Nairobi lies a large estate surrounded by endangered Rothschild giraffes, who have been fed from the window by Mick Jagger and Walter Cronkite.

The world’s first hotel to be run by robots.

The ruins of this antebellum sugar plantation are the end result of a Seminole attack during the Florida Wars of 1836.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

This iron and wood Civil War city-ship was the first vessel to be sunk by an electrically detonated torpedo.

The only home that Alexander Hamilton ever owned has a history almost as troubled as his own.

The largest dinosaur trackway in North America is tucked away among this canyon's ghosts and archaeological gems.

This aquarium has almost as many world records as it does fish.

Nestled in a peaceful valley, this Armenian monastery may have been saved from Mongols thanks to the eyes of God.

Massive prehistoric mammals used these stones as oversized scratching posts.

A massive cave complex boasts some of the clearest water (and most charming bats) in the world.

Crawling into this primordial cave may feel disconcertingly familiar.

The final resting place of Christopher Columbus - or possibly someone else.