If you are visiting Washington, D.C. for the first time, exploring the city's top landmarks is a must. While walking on the National Mall, you get to see the Lincoln Memorial, Washington Monument, and the U.S. Capitol. Smithsonian Museums (like Air & Space Museum, Natural History Museum) are free and provide an amazing experience. Taking photos outside the White House is also a must-do. You can enjoy walking, eating, and shopping in the Georgetown area. In the evening, a Potomac River cruise or the monument night tour are also quite memorable for first-time visitors.