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

A fitting attraction for the corn capital of the world.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

A 56-foot tall statue of the god of fire looks out over Birmingham, Alabama.

Once one of the largest producers of pig iron in the world.

The world's longest known cave system.

Formerly known as National D-Day Museum, this collection commemorates the battles of Normandy and WWII.

FDR hoped to find a cure for polio in this Georgia town's warm springs.

Ride the subways of yesteryear.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

A massive Montreal stadium that has seen nothing but trouble since its inception.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

Hollowed out cedar log tubs set in an ancient towering forest.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

This expansive bridge in the Canadian wilderness was originally just built for friends.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

The US Navy's only submarine museum is also home to the world's first nuclear submarine.

Holding multiple historical boats and an entire 19th century village, this New England attraction is the largest maritime museum in the world.

The only presidential monument to display a late POTUS's actual casket.

The highest bridge in America was built for an almost unnervingly small amount of money.

This historic national park is covered in the stunning ruins of red rock pueblos.

Allowing humans and fish alike to migrate from freshwater to saltwater and back again.