Great for toddlers to preschoolers and beyond - toddlers will appreciate handling the natural wooden pieces and stacking them one on top of the other. The open ended variety of pieces allow for children to imagine many possibilities - creating buildings, cars, boats, and whole scenes. The largest circle piece measures 3 1/2" diameter and the tallest pillar 4". Add some silks, wooden animals or other natural materials from nature..... We offer a 40 piece set here https://www.etsy.com/listing/207131100/branch-building-blocks-40-piece-set? The pieces are untreated and selectively harvested from our homestead in northern Vermont.