When we move about within our environment, we are presented with a range of cues to our motion. Virtual reality systems attempt to simulate these various sensory cues. IVY – the Immersive Visual environment at York – is a virtual environment being constructed at York University to investigate aspects of human perception and to examine the relative importance of various visual and non-visual cues to the generation of an effective virtual environment. This paper describes the movation behind the design of IVY, and describes the design of the essential hardware and software components.