The biggest and deepest Cold War bunker open to the public can be found in southeast England.

This beautiful Victorian ironwork masterpiece was built to keep London from smelling like poop.

Shakespeare, David Bowie, Dr. Who, the Saxons, Druids and Romans are all claimed to have all made their mark on these massive man made tunnels.

This foreboding medieval castle was twice besieged by barons rebelling against the English king.

A perilous medieval road leading right into the sea.

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

This former abandoned hospital, a complex of stunning 19th century buildings, once housed 2,000 psychiatric patients.

This oak sculpture at the edge of a small woodland is nine feet tall and shrouded in mystery.

A woodland close to England's "most haunted village" has been the site of many unexplained events and deaths.

This forgotten chalk mine was reopened thanks to a massive effort from the local community.

Grotto replete with mystical designs laid out in glued shell mosaics.

An anti-tank graveyard in the English countryside.

Two beautiful Victorian-era parks replete with ornamental waterfalls and lakes.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

Two standing giants remain as a tribute to Luxembourg's metallurgical past.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

These quaint French houses dangle precariously over a precipice.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

The fantastic architectural models of a French traveler.

700 iron sculptures crammed into a Mediterranean park.

Walk through living pictures and music in the Cathedral of Images.

This space rocket-like Buddhist stupa sits atop two giant arches and can be seen from out at sea.

This mesmerizing architectural wonder will take your breath away with its unusual color patterns.