Must-Sees in Washington DC

I am so excited to attend NECC this year. NECC 2008 was my first national conference and it was in San Antonio which made it even better! This year is going to be extra special for several reasons:
1. I have never been to DC so I am busy trying to figure out what I want to see and do. I will arrive
sometime on Friday and I will not depart until July 3. That gives me 3 1/2 days to explore.
2. I am presenting a poster session on Tuesday afternoon. The focus in on how virtual schools can help
bring additional opportunities in rural areas of America.
3. I am sharing a room at a bed and breakfast with three teachers that I have never met. I am looking
forward to making three new friends.

I know for sure that I would like to spend some time exploring some quaint, colonial villages. Alexandria might be where I start my journey. If you have suggestions please share them.