The milli-motien, a Caterpillar-sized robot that, in theory, is capable of folding into almost any 3-D shape

So if you were to have a swarm of nanobots all working in conjunction with each other they would be able to create an entirely artificial environment where you would actually think you were in a different place. Like creating a beach or a forest that you would be immersed in it.

As was predicted by Ray Kurzweil