View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

Hear the quietest sound from across the dome.

An unusual round church in London with a Templar past.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

This letter written by Queen Elizabeth II in 1986 won't be opened until 2085.

An Industrial Revolution-era public work that purified water using nothing but sand.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

Is this cat asleep or just pretending?

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

An American city stranded at the tip of a Canadian peninsula where strict adherence to the "49th parallel rule" became problematic.

This Argentinian hedge maze is an intricate tribute to a famous surrealist author.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

Huge stone depressions which may have acted as an Incan agricultural experiment.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

The only castle in North America to ever house European sovereigns.

Part bookstore, part café, and part forest.

66,000 pieces of art, donated by one of the world's richest men.

Climb through the life of a Mexican hero as you ascend a 130-foot statue.

Mexico's astounding mummy museum with "the world's smallest mummy."