Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Walk through Czech history in Prague's largest graveyard.

Welsh literary history is preserved in the delicate pages of these medieval manuscripts.

This Welsh village gave itself a ridiculous name in a publicity stunt a century ahead of its time.

Taking the subway here means doing so over a bridge located in the middle of an estuary.

This famous city eluded concrete detection until the early 2000's.

The ancient latrines of the Greeks, in all their public glory.

A fountain standing as a testament to a doomed alliance.

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

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

The last masonry skyscraper ever built reveals a transitional moment in architectural history.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

This historic hotel invented the chocolate brownie.

On the hills of Bay Ridge stands a house straight out of a fairy tale.

This coffee shop lies hidden beneath a historic church.

The sumptuous ceiling was one of the last things Charles I saw before his execution.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

This Viking gravestone carved in a rare runic style was dug up from a London churchyard.

A clock designed to run with perfect accuracy for 10,000 years.

An artistic tribute to the famous singer, just around the corner from where he was born.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

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