I took my boys here once when we first moved to the desert but they were already a little too old for it. I loved it, though, and wished we had known about it sooner! It’s located in Rancho Mirage and has lots of stuff to see and do. They even have a special space just for toddlers! Go check them out! Children’s Discovery Museum of the Desert
The cost is $9.95 per person over 1 year old, so if you like it, I highly recommend getting a Family Membership for $100 a year. It’s much cheaper if you plan on going more than twice a year, and if you have little people in your house, you will want to go more than twice!