Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This shop for all your super spy needs hides an educational secret.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

St. Augustine's record-setting narrow street was designed to protect against pirates.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

A tribute to Ponce de Leon's supposed quest for eternal youth.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

Arrr! The most authentic collection of pirate artifacts in the world... matey.

Every weekend, people gather here for a brief chance to see their loved ones on the other side of the United States–Mexico border.

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

This curiosity shop contains a museum filled with bizarre, unique objects.

After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

Stairs often replace streets on the steep slopes of this old mining town.

The unusual burial monument of Arizona's first governor.

A living snapshot of a different time in America is preserved and maintained by a community of volunteers.

Walk through the actual strap iron cells and solitary chambers of Arizona Territory’s first prison.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

Collection of vintage trailers double as hotel rooms.

The world's largest military aircraft cemetery.

America's only nuclear missile silo open to the public.

This Art Deco landmark claims to be the longest bridge over the shortest span of water in the world.

This partially completed dam was simply abandoned after nearly destroying the city it was built to service.

The world's largest moose statue is located (where else?) in Canada.

Underground tunnels once home to crime are now back open to the public.