DC is just amazing. Although it's a metropolis, open wide spaces with 360 visibility are common. Being European I got the feeling to stroll in a city for giants. The Mall and visiting places around it are amazing. Georgetown neighborhood is peaceful and nice-looking with impressive piece of architecture such as the university. Nightlife is no less. College bars offer you cheap deals on drinks, good music and surely a worthy night.
Insider Tip:Memorial, air and space museum absolutely with free tour guide, college bars!!