In Bangkok, we visited the Jim Thompson House. The museum is a modern villa made of 7 ancient Thai houses. Together with its garden and ponds, it is an oasis of peacefulness in the middle of a busy city.
Jim Thompson is an American who revived the art of Thai silk. The (mandatory) guided visit focuses mainly on the history of the houses and of the antiques that decorate it. It's definitely not recommended for agitated children who will run around incredibly expensive china vases (although my kids behaved very well during the visit).
On the other hand, all family members enjoyed the quietness of the park and the overwhelming friendliness of the young French-speaking guides who took care of all three children while we were waiting for the next visit. They played with them, offered them origami paper cranes and went together to feed the pond's turtles.
Another great museum experience for our family!
More info: http://www.jimthompsonhouse.com/