Largest Roman Catholic church in North America.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

The most decorated dog of World War I is preserved in the Smithsonian.

There’s a hidden military meme engraved on the World War II Memorial.

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

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

The site of the climactic scene from the classic horror film is now a historic landmark.

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

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

This monument is dedicated to those lost on June 6, 1944, in the town with that day’s highest per-capita casualty rate.

The only surviving 19th-century water-powered mill found in the Washington, D.C. area.

The Aldie Gristmill was once the largest factory of its kind in Loudoun County.

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

The only remaining African American schoolhouse in northern Virginia is now a museum dedicated to formerly enslaved people.

The former home of the man whose radical ideas changed the nation.

These unusual rooms on wheels are holdovers from the 1960s.

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

The romance of early commercial flight still fills this Art Deco destination.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

For nearly a year, General Ulysses S. Grant was based here during the American Civil War.

A former major munitions plant that has been converted into a sprawling art space.