One of the first things we noticed about Hanoi is that the traffic is crazy! There seems to be barely any, if any at all, rules of the road. People drive where they want, when they want. This make street crossings a slightly daunting task. We learned though, that if you slowly walk out into the road and 'frogger' your way across, the motorbikes (the traffic is almost all motorbikes) will drive around you and crossing isn't actually that scary.
Our first destination was the smaller of the two lakes in Hanoi that is right in the middle of the Old Quarter, the main part of Hanoi where we stayed, shopped, ate, etc. The smaller lake is more ornamental and has pretty trees surrounding it. There's a small building in the middle and there's also a small pagoda on the lake accessible by bridge that we visited.
The last thing we did on our first day (other than food of course) was to go visit the other, larger lake. This one is a little further away from the center of the city so it was a bit of a hike. When we got there it was apparent just how large it was. We actually didn't see all of it, we stopped because we'd have to walk pretty far to the road that crosses the lake to see more. There is also a pagoda on that lake too; we could only see the very top of it from where we were standing. Just walking around gave us a good first taste of Hanoi.