I have two variants of this. The 'things from nature' basket which just has shells, wood, stones, feathers etc and 'natural objects' basket including many items from here. This was an easy place to start.
Busy Board - Love this idea! this is a spectacular idea but at the same time i wonder if it would make them want to play with the real stuff more? but my goodness i really really love this idea. pretty sure every toddler would love it.
Smell bags for baby Treasure Basket. Contents: green one contains mint tea bags, purple - lavender, brown - clove, rose - rose petal. To keep the smell - store them in zip-lock bags, only take out when using the treasure basket.