19th century tunnels burrowed under Liverpool.

Six neolithic sandstone boulders remaining from a dolmen.

The centuries-old obelisk may have inspired J. R. R. Tolkien.

The next-door homes of two very different musicians, George Frideric Handel and Jimi Hendrix.

The townhouse where the English poet created some of his most influential work has been preserved in tribute.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

A unique tribute to the millions of animals who served and died for the British military.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

The pockmarks across the building's facade are remnants of the Blitz.

Legend says these colorful, invasive residents are the descendants of birds released by Jimi Hendrix.

This futuristically sylvan church is a glass-enclosed marvel of modern architecture.

This neolithic stone grave has been altered and restored so often its now more neo than lithic.

An abandoned quarrying village turned commune is now a hub for learning the Welsh language.

A modest stone circle in North Wales.

The worst flood disaster in Welsh history might have been a lot worse if it had not happened on movie night.

The stately remains of Llywelyn the Great's mighty fortress.

A hidden tunnel leads to an abandoned slate quarry that's now a secret swimming spot guarded by cliffs.

The highest peak in Wales is said to be the final resting place of a giant killed by King Arthur.

This Welsh hotel is the spiritual home of the British 1953 Everest expedition, the first successful ascent of Mount Everest.

Quirky outsider art transforms this garden shop into a little stone fantasyland.

Western Europe's only representation of a Roman goddess still in its original location sits in an unassuming park.

A rare wooden coffin set vertically into the Gothic arch of an ruined church.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.