Crumbling pink walls and murder memorials preserve the pioneer history of Joshua Tree.

After James Madison's death, his wife and former First Lady Dolley Madison lived in this yellow building near the White House.

This rowhouse doubles as one of the most photographed spots in the nation's capital.

Once home to the largest photo service in the United States.

The only Leonardo Da Vinci painting in the Western Hemisphere.

The grounds of former plantations where abolitionist Harriet Tubman spent her youth enslaved are now a museum to her incredible life.

Inside houses a vast collection of military aircraft and missiles spanning the ages.

You can walk through the first Boeing Air Force One, which famously carried JFK's casket from Dallas back to D.C.

Mass grave of 50 unidentified French Soldiers who died at the Siege of Yorktown, 1781, that gave victory to the American Revolution.

Every autumn, this grove of living fossils erupts in a blaze of brilliant golden-yellow leaves and stinky fruit.

At the western edge of Palm Springs, a rugged desert canyon trail leads to a waterfall at the base of the San Jacinto Mountains.

The ghostly remains of an accidental sea.

An off-grid art installation that encourages its visitors to imagine a world without waste.

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

A hand-built folk art installation covered with messages of God's love.

What looks like a simple quaint estate in rural Pennsylvania was in the 18th century home to a small monastic community.

This memorial honors five journalists who were killed in a mass shooting in 2018, and affirms the importance of the first amendment.

The oldest military monument in the United States.

Rediscovered after a century, the father of the American Navy was reinterred in something dredged up from Davy Jones’ locker.

The National Park Service’s best-kept secret with views that rival any in D.C.

The location where the American Revolution ended.

The crumbling remnants of this 19th-century quarantine hospital hint at the touristy island's darker past.

This small fort played a huge role defending Puerto Rico’s capital city.

The ruins of the first Spanish settlement in Puerto Rico.