The rogue roots are gradually consuming some of the historic marble grave markers.

Hear, smell, see, taste, and touch history at this immersive Civil War hospital.

This museum sits on the site of a decommissioned military communications base.

This sprawling farm was once a Cold War-era hideaway for the nation's top diplomats.

Outsider art meets paleontology at this roadside reptile repository.

Conveniently located within binocular range of a nuclear bunker, the "summer camp" area was a painfully obvious spy house.

Herbert Hoover's "Brown House" rural presidential retreat was a PR disaster amid the start of the Great Depression.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

The first memorial dedicated solely to the Black troops who fought for the Union.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

A painfully obvious spy house sits right across the street from the Russian Embassy.

A wondrous old library overlooking the nation's capital.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

This mesmerizing and surreal landscape features intricate patterns of white and red sandstone.

Petroglyphs, bird watching, and a 100-year-old Ranch in one location.

Some 10,000 works of ancient rock art cover these volcanic basalt outcrops near the Gila River.

One of the most extensive and well-preserved collections of dinosaur footprints in North America.

Once the product of an inexplicable gold strike, this ghost town is now home to one man and his love of classic machines.

A mysterious spirit totem at the edge of Navajo lands.

This striking public art installation is suspended above a public park, designed to gently move in the breeze.

An urban laboratory.