A device for creating a milieu for a creature in a real environment to the creature, the milieu comprising both at least one part of the real environment and at least one fictitious phenomenon, the properties of the milieu experienced by the creature depending on its position and/or orientation relative to the real environment. The device comprises a member for generating stimuli, the member including a transducer arranged to determine its position and/or orientation relative to the real environment by receiving incident optical signals and recording the relative incident directions of the received signals in relation to the transducer, and an element by which the creature and the transducer are connected for generating the stimuli by information about the position and/or orientation of the transducer and about the real environment, and a unit for transferring the generated stimuli to the creature.