There is a floating market in the old city of Ayutthaya which makes a nice change from just visiting old temple ruins all day. Now you can break up your time to make a more balanced day trip from Bangkok. Ayothaya Floating Market - here you can find shops with handicraft and souvenirs.If you want to eat then there are plenty of stalls selling delicious food. You can also take a boat ride around the canal.
Everyone in the family can easily spend a couple of hours at this floating market. As well as shopping and eating, there are also regular shows during the day. These include boat parades as well as traditional dancing at various arenas around the market.