Hidden in the forest atop a long, winding driveway is this stately home.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

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

Through the decades, Black music stars have performed at this historic hub for music and the arts.

The former home of the woman who successfully fought to integrate restaurants in Washington, D.C.

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

After his presidency, George Washington planned to live only a few blocks from the Capitol building.

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.

This cathedral dedicated to Louis IX, sainted King of France, holds many secrets.

One of the first Second Empire-style buildings constructed in North America.

One of the oldest train stations still standing in Virginia played a vital role during the Civil War.

This train station inspired the name of a 1970's rock band and provided the backdrop for their album cover.

This Federal-style plantation house was once visited by Abraham Lincoln to meet with generals during the Civil War.

Get up close and personal at this Fresnel Lens.

Built to defend Washington D.C. during the Civil War, this fort became a post-war nucleus for a thriving Black community.

This cannon dating to 1755 has stood guard at this suburban intersection since 1915.

A small and somewhat hidden memorial to 68 local veterans of the Vietnam War.

Long buried under the 20th-century landscape, this lift lock of the Alexandria Canal is the lone remnant of an ambitious early American transportation project.

This small pedestal marks the spot of the first lot of land sold in Alexandria, Virginia in 1749.

If it hadn't been caught in time, a flaw in the design of this Manhattan skyscraper could have led to its collapse.

This environmental engineering marvel keeps salt water from the Elizabeth River.

A lightship turned museum, outfitted with artifacts from the vessel's past as part of the U.S. Lighthouse Service.

Built in 1945, this historic train station has a new lease on life with its baggage area serving as an event space.

This historic streetcar system has been running since the 19th-century.