A medieval abbey featured on 'Game of Thrones' that dates back to the 12th-century.

A boulder in the Churchyard of Down Cathedral marks the legendary burial place of "The Apostle of Ireland."

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

Northern Ireland's Brobdingnagian stepping stones.

This Italian-style temple replica has been threatening to fall off the Irish coast for hundreds of years.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

Museum celebrating the history of computers, especially their role in codebreaking.

Home to Alan Turing, the cracking of the Enigma code, and Captain Ridley's shooting party.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

Hear the quietest sound from across the dome.

The "beautiful" equation predicting the movement of all electromagnetic particles is engraved in front of Newton's tomb.

This strangely dressed taxidermy creature has a heartbreaking story.

One of England's most famous churches hides a pair of little known architectural treasures.

A set of medieval stained-glass windows tell the gruesome story of a Viking siege.

An impressive armored bronze effigy marks the tomb of one of the medieval era's greatest warriors.

A wonderfully eccentric Victorian-era museum and library.

This skewed English house has looked like it's going to fall over for centuries.

Guests can stay at a hotel in the former French abbey where lie the tombs of King Henry II and King Richard the Lionheart.

Ivy-covered Medieval tunnels cut through this charming town in France's Loire Valley.

A medieval house adorned with enigmatic carvings, including one of a man displaying his masculine attributes.

Do these monsters look familiar? The gargoyles on this church are all from pop culture.

The footprint of a frustrated devil in Munich's Cathedral.

A fearsome dragon clings to a corner of Munich's city hall.