Picture from, Historic Places in New Zealand Magazine, June 1983.
This is said to be a Maori Pa (hill and peninsula fortifications) and within New Zealand there are upwards of 1500-registered Pa sites. The styles of construction are exactly the same as Bronze Age to Iron Age British hill forts. The New Zealand varieties tend to replicate the earliest British styles, where pallisaded barrier fences were erected to keep an enemy at bay. British Archaeologist, Allene Fox, amongst others, commented on the startling similarity between hillfort styles at opposite ends of the globe. The massive undertaking to build so many large fortified positions cannot, realistically, be attributed to the Polynesian Maori, whose advent into New Zealand was in the 13th or 14th centuries AD.