The only international border marker within the United States.

Belly up to the bar in Cowtown, don't forget to buy some boots.

The final resting place of an outlaw, whose legend grew after death.

The final resting place of infamous outlaw Clyde and Marvin Barrow.

A symbol of Texas pride.

A Roman-style column in Oregon hides a spiral staircase inside.

Booker T. Washington's home at the Tuskegee Institute was a gem of splendor.

Yo, Adrian!

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

The world’s first penitentiary, meant to be humane, drove men insane.

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

A beautiful botanical garden in the heart of the Natural State.

One of America's first spies started out as a teacher in this little red one-room schoolhouse.

Celebrating the cultural heritage of Kansas’s premier cowtown.

The real-life site of Ichabod Crane's infamous gourd attack.

These markers are used to document elevation changes around the famed dam.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

A cemetery housing wild west legends in South Dakota.

This erect, phallic geological spire wasn't always named so domestically.

A sharp bend in a dramatic river canyon cut through red rocks.

This 18th-century sundial was designed to calculate the date of Easter each year.

A simple plaque on the facade is the only reminder that the treaty ending the American Revolution was signed inside.

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.