This amazing 15th-century mural remained hidden in plain sight for centuries.

Known as the "Stairway to Heaven," this historic canal dates back to the 1700s.

This reconstructed ancient fort was home to one of the few horse training rings in the Roman Empire.

This police call box harkens back to an era of pre-radio communications, and has a rather unique feature.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

This ancient fort overlooks the site of a disastrous retreat from the English Civil War.

The little-known second castle that William the Conqueror built in York.

An incredibly well-preserved piece of ninth-century Viking poop.

In the U.K., a historic workhouse shines a light on the early, harsh treatment of the poor.

A 13th-century inn where the ill-fated King Charles I spent his last night of freedom.

Once a palace for the Archbishop of York, these 15th-century ruins now serve as a haunt for history buffs.

Glasgow's memorial to the International Brigade volunteers from Great Britain who fought and died in the Spanish Civil War.

This extraordinary Viking artifact has traveled throughout the city.

Brass bricks outline the locations of Edinburgh's lost, lively market stalls.

A free public golf course hides in plain sight in the heart of Scotland’s capital.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

These quintessentially English stepping stones were built for Victorian tourists.

Poetic, metallic giraffes adorn a square off an Edinburgh thoroughfare.

An 11th-century runestone decorates the halls of Terminal 2 of this Scandinavian travel hub.

In the depths of Glasgow Cathedral's crypt, one pillar stands out from all others.

The abandoned transportation hub hides within the Glasgow attraction it once served.

A scattered trail of street art adds a pop of color to the city's stark structures.

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

A secret door leads to this cozy dive that sells only “milk.”