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

This restored house is like a time capsule of the president's unconventional inauguration.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

The farm where one of America's greatest leaders was raised is now a well-appointed landmark.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

The fifth-longest natural arch in the world, and the longest outside China.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Ancient pueblos built into the base of a natural canyon wall.

The unusual patterns in this rock formation result from two distinct modes of weathering.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A tunnel with windows, so you don't miss out on the impressive views.

The abandoned train depot now doubles as a well-placed rest stop for those who take the road less traveled.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

At an isolated roadside rest area stands a monument marking where famous Western star Tom Mix died in 1940.

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

A reproduction of earth's many biomes.

Legend says train robbers stashed their gold within the depths of this unusual cave.

One of the largest open-pit copper mining operations in the entire country.

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

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

If all members were present at the table, a sixth of the world's wealth would be under the same roof.

The only home that Alexander Hamilton ever owned has a history almost as troubled as his own.

Once at the center of U.S. finance, the historic Trading Room was meticulously recreated piece by piece and rebuilt in the Art Institute.

One of the few remaining relics of the meatpacking hub that made Chicago the "hog butcher to the world."