The world's largest Holstein cow.

Spectacular views await visitors to this lake.

The only road through the heart of Glacier National Park.

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

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

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

One man's ambition created this psychedelic log home.

At the time of its completion, it was the tallest dam in the world.

The first declared National Monument in the United States.

Wisconsin's most celebrated export gets the royal treatment on I-94.

This lush 12-acre site was once named the finest Japanese garden in North America.

This unassuming city park is home to three different types of Native American mounds.

This baseball diamond was home to the Rockford Peaches, a team featured in the hit film "A League of Their Own."

The site of an ancient Mississippian settlement that appears to have flourished during the 10th to 13th centuries.

The tunnel that runs beneath this former inn was once a hiding place for enslaved people seeking freedom.

More than 7,000 gallons of water pour over these cascading red quartzite waterfalls every second.

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

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

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

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

Perhaps the most scandalous statue of America's first president.