This giant wooden treehouse within a sprawling garden has its own eatery.

These upturned herring boats make nifty storage sheds for fishing goods.

Twice a day this ancient path disappears with the tides, leaving the Holy Island of Lindisfarne out to sea.

This tiny island is home to the world's largest colony of Northern gannets.

A marine aquarium with an astounding variety of fish hides in the basement beneath the famous Palm House.

The Tudor-style cottage in the middle of the square is not quite what it seems.

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

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

This one has sailed five times as far as Sir Francis Drake's famous ship.

This hidden green space is the city's second largest conservatory.

This Roman amphitheater is said to be King Arthur's legendary Round Table.

A book bound in the skin of an infamous criminal, along with countless other specimens.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

A 18th century graveyard and its astonishing cortege of macabre iconography.

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

These fantastically named natural pools look like something out of a Scottish myth.

One of the oldest scientific gardens in Britain, containing more than 13,302 plant species in its core collection.

A succession of eerily contemplative iron figures lead from a Scottish museum to the sea.