A blank headstone topped with a pile of pennies marks the final resting place of the infamous assassin.

In the basement of the U.S. Capitol Building is a hidden storage room full of ornate floor tiles leftover from the 1850s.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Go take a picture with the inventor of the daguerreotype photographic process.

A historic ruin just 20 feet away from a busy highway onramp.

Before Nixon, "watergate" meant canals.

A portal into the bricked up canal that runs through the heart of Washington D.C.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

Tour the world's largest deep-hole dimension granite quarry, where you can view the plant where gravestones are made and roll a ball down the outdoor granite bowling alley.

The famed architect designed this Minnesota gas station of the future with a lookout tower.

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

Tiny effigies of the victims of Edinburgh's famous Anatomy Murders.

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

This former small-town cinema palace was built with the remains of a luxury liner.

Ruined castle with subterranean vaulted Goblin Ha' or "Goblin Hall."

This picturesque view of the Scottish Borders was beloved by Sir Walter Scott.

An Anglo-Saxon cross inscribed with possibly the oldest written work of English literature.

Stonehenge has nothing on Castlerigg’s views.

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

An Irish cemetery filled with victims of political strife and violent conflict, including the grave of Bobby Sands.

An ancient neolithic tomb that only sees the sun twice a year.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

This short bridge is the only thing connecting a tiny Irish island to the mainland.