This picturesque lighthouse at the edge of the Irish Sea looks like a giant stone pencil.

The inscribed stone at Kilnasaggart is a remnant from nearly a millennium ago.

A peace symbol in Northern Ireland is among the world's largest hedge mazes.

What started as a way to address damp basement walls turned into a house filled with intricate hand-carved designs.

A quaint hamlet of nine cottages around a small green near Blaise castle.

The gigantic skull of a long-extinct species that once roamed the forests of England and Ireland.

There's a labyrinth of manmade tunnels stretching for over an acre beneath Bristol.

A steep and winding road in the Yorkshire Dales passes by these deep natural potholes.

The plunge pool is a surviving relic of a rowdy royal residence.

Much of what constituted mid-century Liverpool now litters a beach outside of town.

This tunnel entrance is built to resemble a grand castle but no one is quite sure why.

These docile dragons are ideal inhabitants for the conservatory greenhouses.

Eighteenth-century home, where Herschel discovered the planet Uranus.

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

The commemorative stone column conceals a secret laboratory.

An open air haven for tropical monkeys in the damp moors of the English country.

Decrepit Victorian public lift is a white-knuckle ride.

Semi-precious Blue John stones have been mined in this cavern system for centuries.

A tiny replica of the iconic London landmark hides on the side of the steel structure.

A labyrinthine underworld of tunnels and caverns hides beneath the city.

The dramatic remains of an abandoned farmhouse sit high on the edge of a remote hillside.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

This network of narrow, medieval passages has the most delightful name.

19th century tunnels burrowed under Liverpool.