This giant, 83-year-old ship elevator is an engineering feat to behold.

Bronze plates placed around this Scottish fishing village form a true-scale model of the solar system.

Hidden in the hills is a mysterious stone structure, known only to a few.

The ruins of an ancient stadium that hosted gripping chariot and horse races.

Tracking the 1,500-year history of Korea's star cabbage.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

The largest earthwork effigy in the world.

A coastal rock outcrop with mysterious inscriptions variously attributed to Native Americans, Portuguese, Phoenicians, Norse, and more.

Native Americans built this circle of stones, which was used to predict astronomical events.

Mysterious ancient boulder carved with petroglyphs in the mountains of Western North Carolina.

Ancient human, animal, and geometric figures drawn in the earth.

America's oldest archaeological site or a muddled case of wishful thinking.

A collection of artifacts from Maryland's maritime past.

A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

Ship skeletons haunt Baltimore's waterways.

Eighteen miniature death-scene dioramas.

The trials and tribulations of marking Poe's grave.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

No one messes with the Massachusetts sacred cod, not this time...

Statue commemorating the use of ether in anesthesia.

The Boston square dedicated to the dark poet who was born nearby.

Painstakingly built dioramas sit unnoticed in a Boston office building.

A plaque memorializes the Boston location of one of the largest nightclub fires in history.

A palatial art deco restroom.