Family fun in Los Altos

I am a frugal kind of gal. I love having fun times with my family that costs little to nothing. Well, that's just what we did on Saturday. And get this, it was right here in Los Altos.
After breakfast at Coco's in Sunnyvale (cost about $15 for all 4 of us!) we went to Los Altos. I love the Los Altos Library and wanted to show it to Rick. So we went over there and found they had a FREE museum about the beginnings of Los Altos. It was fascinating how a whole town sprung up from nothing but a trail station and some old farms. Upstairs in this museum is an interactive section. The kids played with the model train set up to look like Los Altos in 1932. They climbed the horse saddle and played with toy apricots like they were in the packing house. There was a house set up with music playing as if we were in a house in 1932 in Los Altos, California. It was amazing. Now I know what you're thinking. It's free, you couldn't have spent too much time there. You're wrong. We were there for almost an hour before Rick and I made the kids leave. As we were leaving Katie asked when she gets to come back. SCORE!
After that we went to the library. Katie loves to pick out books and borrow them. She got 3 that day. We lost Rick for about 20 minutes as he lost himself in the rows and rows of books. Our friend Jack took Eli to "run" him since he was getting tired and grumpy.
Then we went to the car. Rick and I thought it was a successful day and were ready to go home when the kids spotted the play ground. So off we went to play for about another 45 minutes. All in all we spent over two and a half hours at the Los Altos Public Library complex. Family Fun indeed.
Oh, but that's not all. As we were driving out of the parking lot Rick decided to just explore Downtown Los Altos a bit. When the kids saw the Jamba Juice they begged. So we parked and walked the main street of old Los Altos. We explored a teacher supply/toy store. We saw lots of restaurants we have on our "date night" list. And had an enjoyable time.
It's amazing how you can find fun things to do and stay on a budget if you try. What amazing things does your city have to do?