17th century streets hidden under Edinburgh were once a breeding ground for the black death.

A defensive structure built during the Hundred Years War has remained useful in one way or another for nearly 700 years.

England's steepest street has such a drastic incline that locals tie their parked cars to lampposts when it gets icy.

The abandoned funicular tunnel was a secret base for the BBC during World War II.

An oasis of calm, nestled in the English countryside.

The largest greenhouse in the world is home to over one million types of plants.

An ancient necropolis of magnificent tombs.

Legend says this demonic carving inside a medieval cathedral was one of Satan's minions.

Inside this chapel, Victorian jailers took the separate system to new levels.

The charming collection illustrates life in Lincolnshire in the 18th through 20th centuries.

Modern commuters still pass through this 2,000-year-old Roman archway.

This sculpture marks the spot where one of the greatest Roman rulers was proclaimed emperor.

This innovative steam machine was no doubt the most famous of the pioneer locomotives.

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

A century-old tradition has culminated in a small but singular collection of feline effigies.

One of the shortest streets in York has an especially odd name.

These "bridges" help confused bats cross the road.

The world's largest collection of witchcraft regalia.

An ancient quarry rediscovered by a dog and claimed by biblical kings, a German cult, and the Freemasons.

Abandoned since 1998, this train station has become an oasis for urban explorers.

This strange statue features a bust of the famous composer plopped atop a woman's body.

A giant roundabout made up of six smaller roundabouts can befuddle the uninitiated.

This charming, narrow-gauge railway in the Thames Estuary is sometimes referred to as the "Train to Nowhere."

A chaotic collection of coin-operated slot machines designed to delight and disturb in equal measure.