Yellow Door® Natural Sorting Stones

My toddler spends ages sorting these by size and stacking them, and the smooth, cool surface is perfect for her little hands. They're sturdy enough to survive being dropped on the floor over and over.

The stones have a nice weight and texture that kept my toddler engaged for a solid twenty minutes. I just wish the color variation was a bit more distinct, as some of the similar shades can be tricky for little ones to sort.