This old train trestle and collapsed tunnel once allowed the railroad to negotiate the steep slopes of the Colorado Rockies.

These decaying bridges 1,000 feet high are a reminder of the skill it took to cross the Colorado Rockies by rail.

The final resting place of a 19th-century gold prospector and convicted cannibal.

A real flying saucer, contracted by the U.S. Air Force.

This working class sculpture pounds his hammer all the livelong day.

The spur that wouldn’t die.

Granting the right of way to ships over surface traffic since 1917.

The highest point in New Jersey is marked by a massive, if simply named, obelisk.

These disused steel furnaces are now haunting ruins that may one day be a national park.

Despite being stolen multiple times, this civic electrician's street corner Snoopy won't be stopped.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

This art deco masterpiece was once a miracle spring mecca but is now simply a government office building.

An abandoned factory along the Mississippi coated by a giant mural.

This historic hotel on Bathhouse Row in Hot Springs National Park has a storied history of gangsters and baseball greats.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

I Street Bridge is the heaviest swinging center bridge in the United States.

An eccentric home stands out in an otherwise average neighborhood with mosaics, mini topiaries, and kinetic sculpture.

A dentist's hated concrete colossi are now beloved icons of the community.

The shattered remnants of a meteor that struck Santa Fe more than a billion years ago.

Built in 1895, this bed and breakfast was once a hospital that served an early 1900s Gold Rush boomtown.

An abandoned lot littered with concrete debris was once the home of the world's first female railroad president.

A fine mixture of the old and the new topped with an art deco neon spire.

Established in 1853, this crumbling cemetery sits forgotten on the corner of Church and Chapel in Gold Country.