Opened in 2003, the City Museum of Washington, D.C., focuses on the history, people and ideas of the nation’s capital. In a town focused almost entirely on national and international culture and affairs, the City Museum is an anomaly. Run by the Historical Society of Washington, D.C., the City Museum is a researcher’s heaven: If you’re looking for a good reading room or an archive of D.C-related information, this is it. The City Museum also boasts a theater, galleries for educational exhibitions, a cafe and a gift shop. The City Museum is located within what was once the city’s main library, the Carnegie Library. This 60,000-square-foot structure was built in 1902; it’s one of the very largest of the many Carnegie libraries found in the U.S. The Beaux-Arts design, beautifully detailed with sculpted white marble, is spectacular. You’ll find the City Museum in downtown D.C., in Mt. Vernon Square.