You have to go through a good bit of security to get into the Capitol, but it’s worth it, especially if you’ve never been. Pick up timed tickets early in the morning from the kiosk on the southeast lawn of the Capitol. Because of security restrictions, visitors are only allowed into the building as part of guided tours; visitors are no longer permitted to tour the building alone. more info »

If Congress is in session, you can also contact your congressman to get free passes to watch the House or Senate in action. It shouldn’t be a huge hassle to get these passes, but it may be a good idea to secure these before you leave for D.C.