The powers that be have systematically removed teeter-totters from playgrounds.
I find that sad because teeter totters (aka seesaws) were a great way to learn about leverage. I can remember som fun teeter totters with adjustable fulcrums and I learned that if a little brother changed the fulcrum correctly, the little brother could seesaw against a bigger brother.
I took this photos at Evergreen Park. It shows a new safety teeter-totter with a hand bar and springs instead of a fulcrum.
The pumpkin carriage behind the teeter totter is cool. The safety teeter totter itself is lame.
Now, kids, Remember. If you are going to play on the safety teeter-totter, you need to wear your helmet.
Here is the image piped through a circle distortion: