This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

Legend says this sacred tree was a gift from goddess Athena.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

This seaside sanctuary was once one of the most important religious sites for women in ancient Greece.

The park is home to the United States's only still-operating Dutch windmill.

An angular maze of concrete in Grand Rapids acts both as public art and as a staircase for fish traveling upstream.

This mechanical wonder towers above a river in Michigan's capital city.

Perched atop a brick smokestack, this enormous lug nut symbolizes the local minor league baseball team.

A horse-drawn 1858 steam pumper fire engine encased in glass on the front lawn of a Michigan insurance company.

Collecting 700 years of mechanical death-dealing, the NRA's sprawling gun museum is a revealing testament to the American obsession with armament.

This spectacular mosque houses the second-largest chandelier in the world.

This bazaar is one of the oldest in the Arabian world.

A section of the desert with an array of unusual sandstone and limestone formations.

This remote British Imperial telegraph relay outpost drove men insane.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

This four-story steel sphere in Maryland was used to test biological weapons.

A popular oddity on display in a stately building, offering a symbolic commentary.

The Battle of Atlanta in 360 degrees, featuring a corpse that bears a striking resemblance to Clark Gable.

3/4-scale model of the White House in Atlanta, Georgia.

More than five miles of underground passageways.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

The maze-like transportation hub contains abandoned areas, derelict stores, and a resident bat colony.

The only quarter of the Old City not dedicated to a major world religion.

An ancient tunnel in Jerusalem built to redirect water in the event of a siege is one of history’s great architectural innovations.