I have two daughters at Montessori School of Los Altos and we are very happy there. It is a true Montessori school so you need to research that and be sure it is what you want. While the kids have play time outside where they are free to run around, swing, play in the sand, ride tricylces, etc., in the classroom there are rules and behaviors the teachers model and expect the kids to follow. The children are given a lot of independence to select their learning activities, pick up and put away their learning materials, etc. When you observe the classroom, kids are cutting up bananas to serve to other students or sitting in the library section reading quietly or painting or working with a teacher on the banking game all at the same time. Its quite lovely. If you are concerned about academic placement, my daughter is about to be 5 (Kindergarten next year) and she is reading basic books and doing basic addition - not sure how that stacks up, honestly. But more important to me, in the last two years, she has become more confident. more capable and has made great friends at school. Extra bonuses: swim lessons in the summer (my daughter fully swims as of last summer), cooking their own meals with the teachers on Tues and Fri, and little extras like a bug expert bringing creepy crawlies in for the kids to see as they do a special session on insects. If you are looking for language immersion, it is not that - they do get lessons in Spanish and Mandarin and sing songs in many languages, but if that is your priority, you will need to supplement what they get at this school. Great place - could not be happier.