Semi-recognized center of the world, with many oddities.

An architect's childhood fantasy treehouse made real.

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

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.

The first declared National Monument in the United States.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Come for the speed, leave in love with the desert.

A house carved into a rock in the 1940s.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

This iron and wood Civil War city-ship was the first vessel to be sunk by an electrically detonated torpedo.

A grandiose octagonal home crowned by a large dome stands out among the antebellum mansions.

The final resting place of the camel who served with the Confederate Army during the Civil War.

An eerie and beautiful group of columns mark the site of a grand mansion lost to time and fire.

A half-size replica of the World Trade Center towers above Tulsa.

This small-town museum is dedicated to the original western movie mega-star.

A tiny but mighty little pumper sits in the middle of the street, waiting for the next big oil strike.

One of the best examples of Art Deco architecture in the United States.

The fifth tallest statue in the United States is a shirtless monument to the oil worker.

An oil baron's wild paradise and the winner of an ill-fated air race.

A whimsical tower with a spiral staircase, inspired by the Space Age and the Möbius strip.

Nature's biggest mammal swims in landlocked Oklahoma.

The future of roadside attractions is this sci-fi soda mecca that is home to a 66-foot tall neon pop bottle.