I have a big bag of puzzles we take outside, the larger sized legos are super easy to take out and spot in the grass for easy pick up, play-doh cans and cookie cutters in a bin is easily transported in and out, and all the kids like it when we read outside as a group on "picnic" blankets. We also often use the blankets to make giant forts. Since all of our Little Tikes equipment and play houses are movable if we lump them together we can make hide outs that completely blow the ones we make in the house out of the water size wise.
Lunch and snacks are always fun to have outside too
