A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Washington's iconic carousel has a nice piece of Civil Rights history.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

The walls of the iconic dome are hollow and have a secret stairway.

Home to items never before seen by the public.

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

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

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

The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

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

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.

The only recreation of William Shakespeare's indoor playhouse.