A memorial dedicated to the victims of the Columbine High School shootings.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

At least seven hues of blue and turquoise make this freshwater lagoon unique.

This centuries-old tree tells an unusual tale of vegetation and fertility in the desert.

This 41,000-acre wetland complex is the largest marsh in the interior of the United States.

The grandson of a Kiowa chief created what has become the iconic symbol of a city on the Plains.

Curious rock formations in a tiny Kansas state park.

Small plaque marks the spot, but the true center is located about half a mile away on a private pig farm.

These otherworldly limestone formations jut out from the Kansas prairie.

Once an ancient sea, this landscape of rocky ravines is filled with the fossils of ancient marine life.

The United States's largest hand-dug well is topped with a state-of-the-art museum.

Home to Hollywood history and a very special salt crystal.

The world’s largest combined collection of U.S. and Russian aircraft got its start in a poultry building.

One of the Eight Wonders of Kansas and the first official National Natural Monument these stark formations look like nature's Stonehenge.

This two-room shotgun shack in Tupelo is the birthplace of a King.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

The world's longest known cave system.

One of the longest water bridges in the world was built over a supposedly haunted swamp in Louisiana.

This cathedral dedicated to Louis IX, sainted King of France, holds many secrets.

This "second" cemetery represents New Orleans' attempt to keep cholera at bay.

This historic "City of the Dead" lies prominently in the center of New Orleans' famous Garden District.

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.

A museum and shop on Bourbon Street located in the French Quarter.

The final resting place of New Orleans' most famous voodoo priestess.