Polynesian culture was ordered with laws that were sacred rules, known popularly as taboo, in Hawaii as kapu. While modern usage of kapu throughout the Hawaiian isles is keep out, or no trespassing, that is only a portion of what it used to mean. Kapu rules codified what was acceptable in their society. Like any society kapu covered all aspects of life: gender roles, politics, religion, areas open for fishing, when to harvest trees and so forth.
With no currency, no ownership of property, how would you punish someone for large and serious transgressions, by taking the only thing they owned, their life. Now, there was this very tiny loophole to escape death, a loophole that wasn't easy to wiggle through, but was available, pu'uhonua, a place of refuge. If you could make it to pu'uhonua, then after religious rites and purification all was forgiven, and were free to regain society once again.
The pu'uhonua on Hawaii is wedged between the ocean and the Ali'i Nui (royal) compound at Honaunau. It was not meant to be an easy thing to get to, many were supposed to fail on their journey, so only the bravest, strongest and most determined managed to save their lives. Weeding out the weak in a very Darwin way, yeah?
The building behind the wall is the pu'uhonua compound. During times of war, women and children, elders and defeated warriors took refuge from the battles, no chief would breach the kapu of killing someone within the walls. If the chief of the area lost the battle, the chief took ownership of the land and had a ready supply of people to get back to work. A much better way of waging war if you ask me.
This is the reconstructed temple or heiau that also served as a mausoleum for the Ali'i bones. (royal chief)
Ki'i or more widely known using the Maori word, tiki.