These ruins witnessed the final gathering of the failed Jacobite Rebellion.

One of the largest and oldest caravansaries in Persia.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

This Roman amphitheater is said to be King Arthur's legendary Round Table.

This isolated Japanese mountain village untouched by time showcases unique and stunning traditional architecture.

Ancient barriers wrap around what was once an important stop along the Silk Road.

A sophisticated astronomical tower built by one of the greatest Persian scholars of the Islamic Golden Age.

This Dutch Colonial home is the oldest remaining farmhouse in Manhattan.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

The sinister ruins of one of the worst dam failures of the 20th century lie in this astonishing alpine setting.

This incredible college library is a visual masterpiece of mosaic art. It also looks kind of like a giant boombox.

A charming Spanish village sits atop this natural limestone overpass.

There's a labyrinth of medieval chambers hidden deep below a 15th-century pub.

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.

A dreamy mausoleum honors Persia's most famous poet.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

A breathtaking flower tunnel bursts with beautiful golden blossoms.

Breathtaking Byzantine paintings cover the inside of this 12th-century church.

A fairytale island floats in the middle of Italy's little-known Lake Orta.

An ancient Viking village in North America that predates Columbus by 500 years.

The 43-mile route crosses through six islands with gorgeous views of the Seto Inland Sea.

A boardwalk winds above this beautiful bog full of wildlife and a rare type of turtle.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.