The kofun tumuli have assumed various shapes throughout history. The most common type of kofun is known as a , which is shaped like a keyhole, having one square end and one circular end, when viewed from above. There are also circular-type (), "two conjoined rectangles" typed (), and square-type () kofun. Orientation of kofun is not specified. For example, in the Saki Kofun group, all of the circular parts are facing north, but there is no such formation in the Yanagimoto kofun group. Haniwa, terracotta figures, were arrayed above and in the surroundings to delimit and protect the sacred areas.