Once forgotten, this strip of sand was a rare beachside haven for Black Americans in Atlantic City.

The third-tallest lighthouse in the United States stands as a reminder of Atlantic City's early days.

Designated as an Underground Railroad research site.

Named for a Greek oracle that interpreted the words of Zeus, this beautifully-restored manor home was once home to the architect of the Marshall Plan.

The largest cemetery for enslaved people in Loudoun County was almost lost to history, if not for the research of a minister.

This striking Victorian Home with its 113-foot turret is best known as the site where abolitionist John Brown was executed in 1859.

A glimpse into early 19th-century education.

It is a 50-foot tall sculpture made of a reclaimed wind turbine wing, concrete, steel, and coins from around the world, located off the Columbia Pike in Northern Virginia suburbia.

Northern Virginia’s iconic Vietnamese shopping center.

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

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

A historic arena where the Beatles played their first concert in the U.S.

This one-time communal home of radical feminist activists was the first lesbian-related landmark on both the D.C. Inventory of Historic Sites and the National Register of Historic Places

This nondescript row house in downtown Washington, D.C., was the home of a very secretive group for well over a century

The revival of a classic Art Deco theater.

Art deco landmark on the outskirts of Washington, D.C.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

The Corinthian columns that towered over Abraham Lincoln’s inauguration stand proud.

Once the supplier for noteworthy projects like the National Cathedral, this old brickworks now lies abandoned.

Mysterious rocks that ring musically when struck.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

One of the three perfect vellum copies of this historic book known to exist is on display in a specially-designed case.

This groundbreaking 16th-century map is known as "America's birth certificate."