The heiau most commonly preserved are war temples of the later period of history (e.g. Pu'ukohola Heiau National Historic Site). They are composed of large stone platforms with various structures built upon them. The structures were used to house priests, sacred ceremonial drums, sacred items, and cult images representing the gods associated with that particular temple. There were also altars (Ahu) on which to offer sacrifices (plant, animal and human). The heiau were sacred places; only the kahuna (priests) and certain sacred ali'i (high chiefs) were allowed to enter.