Whenever I'm traveling, I love to spend Saturday morning exploring a local farmers market. You can also find lots of locals there, shopping for their weekly produce, and it's also a great place to sample food from local restaurants.
Every Saturday morning, Old Town Alexandria rolls out a huge farmers market right on the plaza in front of City Hall. You'll find everything from seasonal produce, to crafts, to original pieces of art, to candles, to coffee, to cheese. Get there right when the market opens at 7am for the best selection. Visiting in the winter? No problem—it's year round!