I am all about keeping it simple with toddlers. There are so many things to entertain toddlers that do not involve bells and whistles. We all know water is probably the biggest entertainer of toddlers. Here I just added a few rocks of different sizes, a small cup and an inch or two of water in a large kitchen container. We headed outdoors with it and the toddler had lots of fun, motor skill practice and learning - scooping water, dropping rocks, splashing and exploring the weight and texture of the rocks.
After this initial play phase we added in some small, play toy animals. I thought she would enjoy this change. Come to find out she just took all of the animals out and continued to play with the rocks and the cup.