In order to navigate, move, and behave intelligently, all animals must mentally represent the spatial structure of their environment, like the locations of objects, agents, and landmarks. Yet, all these spatial relationships can be represented in disparate spatial reference frames, some defined by the sides of the body (e.g. my left-right) and others defined by features of the external environment (e.g. East-West). In this talk, I bring together findings in children and adults, and in US Americans and indigenous Amazonians to address three key questions about the diversity, development, and dynamics of these fundamental formats of spatial cognition, including (1) why people across contexts vary in the reference frame they prefer, (2) which reference frame children are predisposed to use, if any, and (3) how different reference frames interact in memory of a single object.