Virtual Reality
To experience virtual reality (VR) in all its true glory you need to put on a set of VR goggles. The screen in front of your eyes shows a 3D World and when you turn your head you appear to be moving within that world.
Speakers transmit the sounds from your artificial environment to your ears and you may be able to wear other sensory devices that give additional feedback, such as gloves that vibrate when you touch something. All of these effects conspire to lull your mind into thinking that you have entered a different world.