One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

The oldest continuously operating fish market in the United States.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

Largest Roman Catholic church in North America.

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 hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

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

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

Elevated freight railway turned wildly successful urban park.