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

The high point on the 16th president's eponymous roadway is marked by a massive version of his head.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

Native Americans built this circle of stones, which was used to predict astronomical events.

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

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

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

The world's largest Holstein cow.

A true roadside icon standing on the same plains that the herds once roamed.

This long unused shot tower on the Mississippi remains a point of pride for a small city in Iowa.

A pop-culture attraction outside of Dyersville, Iowa, hits a home run.

An obelisk commemorating Lincoln's role in connecting the coasts.

This family driveway also serves as the highest point in Illinois.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

This scenic overlook commemorates the tragic death of a soon-to-be-married lumberjack.

A popular place to pick up prehistoric coral fossils from the time when Michigan was an ocean.

Legs Inn provides Polish food, a cornucopia of Odawa artwork, wood carvings, and mounted deer heads.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This shallow cave got its name from copious amount of human bones found inside.

This lighthouse and shipwreck museum keep a torch burning for the memory of the SS Edmund Fitzgerald.

"The Most Boring Road in the State."

This freshwater spring fills with 10,000 gallons of water per minute.

This picturesque cliffside beacon no longer calls to sailors but shines once a year in honor of a famous shipwreck.