The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

A beer pipeline runs beneath Bruges.

The city of Manchester quietly unveiled this tribute to a 19th-century massacre.

A monument to the real explorer and bear who inspired characters in Philip Pullman's 'His Dark Materials.'

These lamps were created to expel sewer gases after an event known as The Great Stink.

In a small courtyard resides this large mural that draws inspiration from Leeds and its history.

These steps offer a breathtaking view of one of Europe's most besieged fortresses.

This Roman relic was discovered in Scotland by a mudlarking ferryman.

A moody and picturesque riverside ruin overgrown with vegetation.

England's largest white horse isn't even white.

An abandoned 6th-century monastery features a medieval map of the known world.

Terrifically morbid cemetary and site of famous Paracelsus' grave.

Cold war icon and onetime "hole" in the iron curtain.

Built in 1911, the Tees Transporter Bridge is one of only six transporter bridges still in operation.

This enormous sculpture honors an English town's engineering and industrial heritage

Originally meant to hold a statue of King William IV, this support sat empty for years. Today, it hosts a rotating cast of public artwork.

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

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

This cannonball embedded in the side of an Edinburgh house once served a surprisingly pedestrian purpose.

If you visit the burial place of King Frederick the Great, you'll likely find a couple of potatoes sitting on his tombstone.

Winner of the Leeds Award for Architecture and the Environment.

At 22 feet tall, these Bronze Age monoliths are some of the tallest standing stones in the United Kingdom.

A stained-glass window from the 15th century offers a vision of the end of the world.