SandScape is a tangible interface for designing and understanding landscapes through a variety of computational simulations using sand. The simulations are projected on the surface of a sand model representing the terrain; users can choose from a variety of different simulations highlighting height, slope, contours, shadows, drainage, or aspect of the landscape model, and alter its form by manipulating sand while seeing the resulting effects of computational analysis generated and projected on the surface of sand in real time. SandScape demonstrates an alternative form of computer interface (tangible user interface) that takes advantage of our natural abilities to understand and manipulate physical forms while still harnessing the power of computational simulation to help in our understanding of a model representation.