and across from adelphi is via via a good pizza/italian place..

personally i would want the pool however....

a klong tour is easy....go to taskim pier and there is a kiosk there to arrange it....

Thanks everyone for your help. I wound up making a reservation at the Holiday Inn. Looks like a good neighborhood for food, access to the skytrain, and potentially taking the train back to the airport. We will probably fill our day with a klong tour and as many meals as we can.

(Craig-saw your suggestion re cooking class but my son is more interesting in the eating than the cooking!)

When you are riding the skytrain down to the river from the Hol Inn, try to take note of the robot building! I think your son would enjoy it. It is near the Chong Nonsi stop. It is possible to get off the skytrain, take photos from the platform and get back onto the next skytrain, if you want to have a better look at it. I have done this before. You do not exit the BTS so no using another ticket to get back on.

I stayed at this Holiday Inn a few years ago and thought it was a good choice for me. Hope you like it too. You will be close to Central World mall which has loads of dining options. You will also be only a couple of stops from the Nana stop which has Kinnaree on soi 8, for good Thai food, which I mentioned above; also Via Vai for pizza(the best in BKK in our experience).
Carol