Its diverse collection of computers and technology spans the ages.

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

This one-room cabin where the young colonel slept during the French and Indian War.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

This bell is one of the last remnants of the lost city of Triadelphia.

This abandoned fortress still stands guard over the Guadiana River despite a history of warfare.

Owned by Native American women, this brewery is a celebration of indigenous culture in the American Southwest.

An eponymous directional signpost erected by the first president of the United States.

The oldest arched-covered bridge in Virginia has truly withstood the test of time.

The Grand Ole Opry's big voice came from a small home in rural Virginia where she was eventually buried.

The Virginia home of one of the signers of the Declaration of Independence is being preserved with a unique glass facade.

The Virginia farm where John Wilkes Booth met his grisly end is now largely forgotten.

Lines from a walking song are etched into a rock in Natural Bridge State Park.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

A magnificent, long-abandoned castle built in the wake of the reconquest of Spain.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

The medieval castle built as headquarters for the Pope's secretive Knights Templar.

A stunning medieval castle houses this eclectic, interactive tribute to all things wine.

The effect of this ancient form of image projection situated atop an 11th century Moorish palace is thrilling.

This small and often-overlooked museum holds some of Spain's finest artistic treasures.

The little church's beautifully frescoed ceiling has earned it the nickname “the Sistine Chapel of Madrid.”

Looking strangely like Rome's Colosseum, this unfinished tower has dominated the skyline for over 100 years.

Historic medieval fortified city in southwest France.