I've always wanted to run the National Mall. It just feels like the ultimate local thing to do... I know, it's weird. But even though I enjoy running in strange cities, DC feels more like a hometown when I bike or run it. It feels like "hey, I'm local enough that I can run here and not care about how gross and sweaty I am, because a shower and snacks await me at my house!"
So we started near what will the T1 transition area- not far from memorial bridge where all the playing fields are. We ran the war monuments, then up by the reflection pool, then up to Lincoln. If you've seen the second Captain America movie, you know the route.
Then we ran all the way up the Mall. I paced M pretty well. On the way back down, he went and did a few out and back sprints. This is a great way to run with someone faster than you- have them run to a certain point, and then they come back towards you. So he'd run two lights down and then come back and meet me. It's a good way for the slower person to get a little speedwork in too- start running faster when the fast person is spotted coming back to you! Sprint to meet him or her, and then you get a little interval in!