I managed to get upto the top of the washington monument on the second day. The map exhibit at the Walters art museum was good. Here's an interesting map from 1677 by John Adams. And this looked way better full size.
I sat through the biggest storm I have ever experienced today. The rain was coming in waves across the grass at about 55 mph. It was pulling grass out of the ground . Moments later it hailed and was completely calm. Given the weather there was no flying (it was supposed to be a practise day) so we ended up doing this instead.