The intended purpose of this unfinished Elizabethan building remains a mystery.

This abandoned gun tower was built to defend the River Thames from a French naval attack.

The artist David Nash planted a circle of trees in 1977.

An ancient woodland that inspired a young J.R.R. Tolkien.

Legends say that this small island was the final resting place of the Welsh saint of lovers.

This stone throne invites adventurers to observe breathtaking views of the Peak District.

For part of the year, this innovative greenhouse is painted white to keep the plants from getting scorched.

This amazing trail among the many waterfalls around Ingleton has been enchanting visitors since 1885.

A Neolithic burial site built 1,000 years before Stonehenge.

The National Railway Museum in York is the largest railway museum in the world, attracting almost 1 million visitors per year.

There's a strange stone hoodoo towering atop a wooded hillside and no one is quite sure how it got there.

The location of the Bridge of Death and the Gorge of Eternal Peril in "Monty Python and the Holy Grail."

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

Great Britain's only hat-making museum.

This former Welsh metal factory is now a lovely abandoned relic but was once one of the industry's world leaders.

This tiny train shuttles passengers to one of Northern Ireland's most spectacular sights.

An amazing collection of curiosities hidden in a small Welsh village.

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

One fisherman has used his love of pebbles and shore to create a crazy garden of rocky art.

Henry VIII's forgotten castle was built by the gunpowder-obsessed king to be defended solely by cannons.

The wreckage of an old coastal trading vessel is only visible at low tide.

One of the few surviving street funiculars in the world.

A mysterious crater-like pond has a spooky tendency to empty and fill with complete disregard to rainfall patterns.

Recently restored menagerie of Victorian-era beasts.