Bring the instinctive wonder that children have for nature into the classroom with an organic, wooden building blocks set. The Wood Stackers River Stones invite children to build and stack using blocks inspired by the natural, polished shapes of river rocks. The rounded, wooden stones are sanded incredibly smooth to highlight the beautiful, natural grain and tones of the wood pieces. Different sizes help children understand weight, gravity and relationships. Inspiration cards encourage children to build creatively using the natural blocks to create familiar objects and encourage exploration in nature. For indoor/outdoor use. Store indoors in a cool, dry place out of direct sunlight. Set of 20.