Abstract: A natural daylight window simulation unit includes a thin supporting structure, a sheet of transparent material with imprinted indicia thereon representing a view, supported in this structure, and a thin, natural-like daylight backlighting system provided in supporting structure for supplying evenly diffused backlighting to the sheet of transparent material, to create in combination with the imprinted transparency a simulation unit supplying natural daylight especially to a windowless interior. The simulated daylight window units can be made in the form of a window or a skylight or a door with window panels.