The remains of a historic plantation nestled in between a parking lot and the rental car return at Reagan National Airport.

Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

A six-story-tall golden pyramid, surrounded by a moat.

A winding district gerrymandered into the shape of a mantis.

The whole world in one water tank.

Three abandoned missile silos are hiding in plain sight behind a suburban development in Maryland.

The brainchild of Eleanor Roosevelt, her "Little Village" was a collectivist dream.

This four-story steel sphere in Maryland was used to test biological weapons.

A star fort along the C&O Canal in western Maryland that protected America in three wars.

Berkeley Springs State Park boasts the nation's only monument commemorating presidential bathing.

Maryland's first (and last standing) toll house on America's first federal road established the state as the "Gateway to the West."

This one-room cabin where the young colonel slept during the French and Indian War.

The ruins of New Zealand's largest classical-style church.

Bullet holes in the church wall are a reminder of the violence that followed the assassination of a high-ranking Nazi officer.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

This lovely pocket park is one of the most under appreciated in D.C.

The oldest continuously operating fish market in the United States.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

Gargantuan home of Russian science.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

The oldest operational cathedral in the U.S. has one shell of a way of projecting speakers' voices.

Mexico's first public cable car soars over the congested streets outside Mexico City.

Frida Kahlo's childhood home, now a museum of her life and works.