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

The world-record holder for the longest bridge stretching continuously over water.

When flour explodes, it's not a pretty sight.

A little-known memorial to servicemen and nurses killed in the line of duty during the First World War.

This staircase full of Mayan hieroglyphics is perhaps the largest single text in the world.

Three hundred years of preserved Spanish colonial history in San Antonio.

This replica of the Greek structure is in the heart of Nashville.

Once the site of a Native American harvest festival, this humble clearing later played an invaluable role in the birth of jazz.

This distinctive Crescent City tradition dates back to the days of horse-drawn carriages.

A small park on Bourbon Street features life-size bronze statues of New Orleans musicians.

An impressive collection of farm equipment and other artifacts from life on the prairie.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

The first declared National Monument in the United States.

Before he was America’s most famous preservationist, John Muir was an ingenious mechanical inventor.

At this Minnesota state park you can easily wade across the source of the mighty Mississippi.

Equal parts record-breaking temple to consumerism and bizarre fun park, it's more than you think it is...

This old residential building was once the largest flour mill in the world.

The oldest house in Galena, Illinois, now is a reminder of when this city was the world's lead mining capital.

Home to the Amorphophallus titanum "Corpse Flower," which is among the largest flowers in the world and also smells powerfully of rotting flesh when in bloom.

One of just a few cities in the world to base their center of government on an island. Others: Paris and Osaka.