Deciding that you will take a day to see the Smithsonian Institution is allowing too little time, as the Institution is much wider in scope than you may have originally thought. It actually encapsulates 19 museums as well as the National Zoo, all home to must-see exhibits and attractions. Some of the more popular stops within the Smithsonian include the National Air and Space Museum, the national Museum of American History and the National Museum of the American Indian. The depth and breadth of everything here justifies the time and space that it takes to see it all.
Seize the opportunity to see our government in action with a visit to the Supreme Court of the United States. The Neoclassical architecture of the building is stunning, and the outer spectacle of the Court is just the beginning. While the court term runs from October through June, you can actually sit in on an actual Court session. Seating is limited, however, so plan to arrive early at the Front Plaza if you want a seat. When the Court is not sitting, you can still take in a lecture or presentation every hour on the half hour.
The two of you deserve to put some artistic flair into your romantic time together, and there's no better place to do that than the John F. Kennedy Center for the Performing Arts. America's memorial to President Kennedy keeps an artistic tradition alive that would have put a smile on the face of the beloved fallen leader. There are 7 different theaters in the venue that are always featuring such works as ballet, dance, opera, symphonic presentations and so much more. There are enough places on the grounds for the two of you to sit and enjoy each other's company before or after whatever production you have decided to take in.