Camera obscura means “dark chamber.”  Camera obscura is an optical device that led to photography and the photographic camera. The device consists of a box or room with a hole in one side. When light passes through the hole, it transmits an inverted image of the object or scene that is outside the box or room onto a flat surface that is inside the box or room. The inverted image can be projected onto paper, and thereafter traced to produce a highly accurate representation.
 In the fourth century B.C., it was Aristotle who first mentioned about it and it has aided artists in drawing for centuries. The Constitution Hill in Aberystwyth, Wales has the largest camera obscura in the world.