To find the "unicorns of the deep" you've got to go downstairs.

This awkward aquarium sculpture is one of the strangest statues in Chicago.

A goddess-topped water fountain in Chicago was created thanks to the dreams of a thirsty newsboy.

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

A display of magnificent stained glass windows is the first exhibit of its kind.

Chicago's Navy Pier on Lake Michigan was a training hub for aircraft carrier pilots during WWII.

Profile of a sleeping person four kilometers long in 250-meter-high cliffs.

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

Legend has it the commander of the defenders drew a fateful line in the dirt with his sword just before the final battle.

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

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

The clock that sets them all.

When an ancient supervolcano erupted, some of Nebraska's prehistoric animals were forever preserved in ash.

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

An experimental, automotive replica of Stonehenge.

America's largest man-made forest was planted in an effort to bring back the past.

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

Hidden behind Lincoln's head is a chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

One of America's first dinosaur parks gives a window into Depression-era paleontology.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.