An 'augmented reality sandbox' sounds like the kind of standard iOS app that we were all amazed by in 2007, and now ignore in favour of Candy Crush Saga.
But then you realise we're talking about an actual box filled with sand, just turned into a complex world building sim, and you realise this is actually incredibly awesome.
The idea is that kids can build their own worlds, compete with water, vegetation and even life, by manipulating the shape of the land by moving sand.
University of California researcher Oliver Kreylos built the strange device with a Microsoft Kinect camera, a projector and a standard computer.
"The resulting augmented reality (AR) sandbox allows users to create topography models by shaping real sand, which is then augmented in real time by an elevation color map, topographic contour lines, and simulated water. The system teaches geographic, geologic, and hydrologic concepts such as how to read a topography map, the meaning of contour lines, watersheds, catchment areas, levees, etc."
Take a look below.