The human brain appears to have several "regions" that are structured to do different kinds of spatial thinking, according to a large and rapidly growing body of research in a number of disciplines. Building on a previous review of research with older children and adults, this article summarizes the research on spatial thinking by young children. Three conclusions: brain structures for spatial reasoning are fully functional at a very early age, adult intervention can enhance both use and representational ability, and practice in early grades is an important, perhaps even essential, part of the scaffold for later learning. (Contains 2 figures and 1 note.)