Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

This shifting North Carolina sand dune is an odd little desert surrounded by oceanic forest life.

Three and a half miles of cliffs, rocky beaches, Gilded Age mansions and 40 Steps to nowhere in particular.

Once the most flame resistant building in the country, the South Carolina Historical Society building was almost burnt down in a fire.

This replica of the Greek structure is in the heart of Nashville.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

Hidden for 165 years inside a building designed by Thomas Jefferson are the remains of what may be America's first educational chemistry lab.

Edgar Allan Poe's old dorm is now a shrine to the author's legacy.

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

Memorializing an American tragedy of massive proportions.

A model of a dinosaur that was named for Andrew Carnegie stands outside the museum that also bears his name.

An 18th-century Catholic church converted into an eccentric temple of music and bacchanalia.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

This dramatic rail curve was once the target of a failed Nazi attack.

Behold the rickety wooden glory of the world's oldest operating roller coaster.

Steepest flood safety railway in the entire world.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

An abandoned stretch of highway, deteriorating next to the operational one.