There was a top secret plan during World War II to seal a group of soldiers inside the rock.

This private home is famous for appearing in the cult-classic "Twin Peaks" series.

A brick-paved former section of the historic coast-to-coast highway.

A spiral staircase connects the limestone cave with Pembroke Castle, birthplace of King Henry VII.

Dead weights honor the dead of Portugal's fishing industry.

This lake-bound geographical marker sits at the point where three European countries intersect.

All that remains of the fishing-vessel-turned-warship is its weathered hull.

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

This beautiful example of Victorian engineering is the oldest water-balanced funicular anywhere in the world.

The largest brick bridge in the world.

A locomotive made from 185,000 bricks celebrates the town's pioneering railway history.

An impressive century-old, to-scale topographical map of Guatemala.

An eccentric aristocrat brought these Australian natives to their current Scottish home.

The world's first and only three-segment bascule bridge folds up into the shape of a capital "N" to let boat traffic through.

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

This tiny business claims to be "the smallest pub on the planet."

This doorless 20th-century elevator doesn't stop or slow down.

This soviet pilot's graveyard is filled with headstones made of airplane fins.

A preserved Nazi labor camp now has a Holocaust museum on site and memorials to the thousands that died while imprisoned at the camp.

Rare karst landscape eroded from a flat seabed.

A popular day's outing in Bovington consists of watching military tank driving practice.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

An optical Illusion once believed to be an electrical phenomenon.

The strange phenomenon causing gravity to "work backwards" on this hill has been blamed on the paranormal.