You could build an interactive 3D simulation of just about anything. The key focus industries have for many years been gaming and entertainment, but actually the medium is ideal for teaching and demonstrations as well as many other practical applications.
VR and AR are of course not just visual. They can use audio for music, voice and sound effects, as well as photography and video – even aromas and tactile perception. It can also implement real-time data like GPS co-ordinates.