These markers are used to document elevation changes around the famed dam.

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

The small town of Poulsbo in Washington state is the next best thing to the Kingdom of Norway.

Interactive modern and vintage submarine equipment, World War II relics, and submarine attire.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A Roman-style column in Oregon hides a spiral staircase inside.

Experience a charming 1930s version of "infotainment."

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

A museum dedicated to the alleged Roswell Incident.

The Grand Canyon of Texas.

A sculpture made of 10 Cadillacs as a monument to the “Golden Age” of the American automobile.

The stickered marker pinpoints where the only maintained road in the United States crosses into the polar region.

This mile marker stands at the unofficial end of a highway built to defend the United States from a Japanese invasion during World War II.

A trading post in the North Pole where children send letters.

"Only the devil could play golf here."

Belly up to the bar in Cowtown, don't forget to buy some boots.

The "world’s largest honky-tonk" also has its own indoor rodeo arena.

The only diamond mine in the world where you can keep what you find.

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

A theme park featuring a replica of Noah's Ark built to the measurements specified in the Bible.

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

This Canadian monument to the man who invented the telephone allows visitors to get up close and personal with the artifacts of his life.

A monument celebrating the idea of reaching inaccessible places.

An idyllic swimming pool tells the tale of Hemingway's trouble with women.