The ahus (pronounce a-hu), open sky temples dedicated to the worship of ancestors, are stone terraces on which are raised the famed moais, monolithic statues of black volcanic tuff. Ahus are central to the Rapa Nui religion. The moais that are erected on them represent an incarnation of ancient tribe chiefs whose stare concentrate and transmits the power received from the sky (mana or spiritual energy) to the village it is facing. This is why all moais look toward the inside of the island.