A mysterious carving from 17th-century London seemingly depicts a young boy sitting on a bread basket.

World's first "penitentiary," meant to be humane, drove men insane.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.

This skewed English house has looked like it's going to fall over for centuries.

One of England's most famous churches hides a pair of little known architectural treasures.

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

Get up close to emus and ostriches, or buy their tasty meat.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

The romance of early commercial flight still fills this Art Deco destination.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

Megachurch turned Catholic church comprised of 10,000 glass panes.

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.

This massive redwood tree has a hole in the base big enough to drive through.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

Historic funicular railway, believed to be the shortest railroad in the world.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

The world's longest known cave system.

The private clubhouse for the members of the Academy of Magical Arts.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.