A great place to take kids that’s nearby is play located in Downtown Los Altos.  My kids love the variety of toys which seem to be switched out constantly.  They have a reading corner, foam pit for kids with lots of energy, craft room, building blocks, costume closet, thinking toys, a music area in addition to yoga, music teachers, etc.
There’s a new theme each week so there’s always something new to create and explore.  This is one of those best kept secrets around here and one place my kids always request we go.

From our last few visits: