Make a backyard bowling alley. Add food coloring to clear plastic bottles of water. Use party streamers as lane margins. Add glow sticks for night bowling. (These would make great outdoor table nightlights also with the glowsticks, gonna try it!
How to Make a Leak Proof Water Blob (without tape! We did a blob last year. The kids loved it. And it leaked. I looked over how she does it (iron-genius!) and am excited to give it a try. We added glitter to our water to make it a little more fun.