Pa site Y17/178 is large ridge top pa that forms part of the dense archaeological landscape of the Tolaga Bay (Uawa) area. It is located at the northern end of a north-south ridgeline on Mangeheia Station, west of Tolaga Bay. This pa is one of the numerous pa that have been recorded in the Tolaga Bay area, mostly located on the prominent hills and ridgelines which afforded excellent natural defences and provided commanding views of the surrounding landscape. These pa and the many other archaeological sites recorded in the Uawa region such as pit and terrace complexes, midden, gardens and urupa reflect the intensive occupation of this landscape by Maori from the time of initial Polynesian settlement approximately 700 years ago. Access to abundant food resources from the sea, rivers, inland forests and horticultural production (kumara) meant that a large population could be sustained. It has been estimated that the early Maori population of Tolaga Bay totalled approximately 1200; and the main iwi was Te Aitanga a Hauiti. Pa site Y17/178 is located in pasture at the northern end of a north-south running ridgeline, approximately 560 metres west of the northern end of Mangeheia Road, where several houses are located. It provides strategic views of the surrounding landscape, particularly north to Paroa Station, where a number of pa are located. There are several other recorded archaeological sites in the vicinity of the pa, such as pit site Y17/177 and pit/terrace site Y17/176 to the east and northeast respectively. This pa was first recorded by archaeologist Kevin Jones during his archaeological survey work in the Whangara, Tolaga Bay and Uawa Catchment areas in 1982-1983. This survey work was undertaken to gain information about the nature of prehistoric settlement in this locality, and also to evaluate specific sites for registration under the Historic Places Act 1980. Jones described the pa as a 'ridge pa with multiple pits & terraces' and later estimated that the total length of occupied ridgeline was 320 metres. He also estimated that the pa could have sustained a population of approximately 63 individuals. He did not locate any obvious artificial defences such as defensive ditches, but noted that the terrace scarps on the west-facing ridges may have served a defensive purpose. Jones also noted that the pa was heavily eroded by stock. Pa site Y17/178 was revisited by archaeologist Vanessa Tanner in 2000 as part of the New Zealand Archaeological Association Site Recording Scheme Upgrade Project. Tanner found the site to be as previously illustrated, but some of the archaeological features were vague as a result of ongoing stock damage and slumping. No major changes were observed during a New Zealand Historic Places Trust site visit in November 2007. Pa site Y17/178 is one of the numerous pa recorded in the Tolaga Bay area, particularly in the Mangaheia Valley, and it is part of a much wider archaeological and cultural landscape that is of considerable significance to Te Aitanga a Hauiti. This landscape reflects the intensive Maori occupation and settlement of the Tolaga Bay area since the 14th - 15th centuries A.D.