The only public school for Black children in the region from 1895-1936.

This golfball sized platinum iridium cylinder is the official starting point for all national weight calibrations

The U.S. government built the million-pound stack of steel during the Space Race.

Bizarre Cavern.

The hidden ruins of a mill that is linked to an attempt to assassinate the vice president of the United States.

Once the center of a thriving early Black community called Martinsburg.

Built by the patriotic residents of Boonsboro in a single day.

One of the only memorials dedicated to journalists who died in combat.

First built around 1848, this bridge was destroyed by arson, but original timbers are included in the replacement.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

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

Born a slave on the Arlington estate, Parks dug the first graves at Arlington National Cemetery, and was buried there, too.

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

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

This abandoned Victorian-style house was built in 1884.

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

The ruins of an old mill lie in a small ravine along a hiking trail near Little Seneca Creek.

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

According to local history, this cast-iron canine was nearly melted down for bullets during the Civil War.

A Civil War Museum with some notable medical antiques.

Historic barracks utilized during both the Revolutionary War and the Civil War.