Given that this is a city with a long, complicated history, there have to be a few ghosts roving around the city, right? Hear about conspiracies, assassinations, and murders that took place right where you're walking. This may seem like a Halloween activity, but honestly, ghost tours are even more fun during seasons when spookiness isn't the standard. Tickets are $17 a pop for adults.
The Mansion on O Street offers a variety of delightful tours and hunts, including a Champagne Tour (precisely what it sounds like), and a Penthouse Tour of the mansion's famous secret passageways and concealed doors -- including the Penthouse Suite -- but the most inspiring, by far, is the Mrs. Rosa Parks tour. The famous civil rights activist was a resident of the mansion for over a decade, and the tour offers visitors a chance to "visit her favorite rooms, view mementos, and hear inspiring stories of how she touched us all." $50/person.