This giant iron playfully pays tribute to an early 20th-century architectural trend.

An ancient cave system in Tennessee’s Appalachian foothills converted to a 1,200-person music venue.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

The world's largest version of this iconic puzzle cube is located in Knoxville, Tennessee.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

The statue mysteriously lost its head and left hand.

Before TV meteorologists, there were weather kiosks. This may be the last one in the United States.

Formerly the world's largest, this Willy Wonka-esque contraption runs 24/7.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.

This Las Vegas casino boasts one of only three spiral escalators in the United States—an engineering wonder.

The bullet-riddled wall from the St. Valentine's Day Massacre, bloodstains enhanced for your viewing pleasure.

One of the few surviving original NASCAR dirt-track speedways.

Scenic mount trashmore, Virginia Beach's most curious waterfront still has a couple of secrets.

Metal dinosaurs lurk in a sculpture garden on the outskirts of a popular resort town.

A museum dedicated exclusively to aircraft used in the military.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."

A hidden courtyard houses early 20th-century plaster masterpieces.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

This stunning home looks like it belongs in medieval Europe, not North Carolina.

This North Carolina store preserves a historic moment in America's movement for racial equality.

An underground city of salt.

Too much gossip or just missing curfew could land you in here for a couple of days.

The world's newest astronomical clock is also its most accurate.

The 700-year-old fortress was the site of Count Orlok's castle in "Nosferatu."