Originally the Khmer prang temples were for the worship of the Hindu gods, such as Shiva and Brahma. The space within the prang tower, the cella, was relatively small for two reasons:
The rituals which were held in them were reserved for a small elite (in the capital of the Khmer only the god king could enter the shrine).
The technology of the Khmer could not yet make large airy halls. (Ringis, 1990)