Haparangi is a small terraced pa that forms part of the dense archaeological landscape of the Tolaga Bay (Uawa) area. It is located on Iwinui Station, Tolaga Bay, on Haparangi hill at the confluence of the Waimanu Stream and Uawa River.

Haparangi is one of the numerous pa that have been recorded in the Tolaga Bay area, particularly in the Mangaheia Valley to the northwest of the township. They are mostly located on the prominent hills and ridgelines, which afforded excellent natural defences and provided commanding views of the surrounding landscape. Together with the many other archaeological sites recorded such as pit and terrace complexes, midden, gardens and urupa, they reflect the intensive occupation of this landscape by Maori from the time of initial Polynesian settlement approximately 700 years ago. A large population was able to be sustained by access to abundant food resources from the sea, rivers, inland forests and fertile soils, which were well-suited to kumara gardening. It has been estimated that the early Maori population of Tolaga Bay totalled approximately 1200; and the main iwi was Te Aitanga a Hauiti.

Haparangi was possibly occupied contemporaneously with the pa on Taharangi hill (Taharangi pa Z17/3 and pa site Z17/5), and the nearby village (Z17/24) on the western bank of the Uawa River. These sites were occupied in 1835 when trader Joseph Polack visited Tolaga Bay. They have also been registered as part of the Taharangi and Haparangi wahi tapu area (Record Number 7461), nominated by Te Whanau a Rangiuia, and endorsed by Te Aitanga a Hauiti.

Haparangi is located at the level eastern end of Haparangi hill, overlooking the Uawa River and Waimanu Stream, and with strategic views to the settlement of Tolaga Bay to the east, and Titirangi hill to the southeast. It is currently in pasture, with dense thistle coverage in some areas, and can be accessed via the farm track that runs along the ridgeline. Haparangi is a small pa, occupying approximately 50 metres of ridgeline, and it has been estimated that it could have supported a population of approximately 14 individuals.

Haparangi was first recorded by the Gisborne Museum in 1971, and was described as a 'terraced hill top pa'. A site plan was completed showing three distinct terraces in a row along the northern part of the site, and two pits (one large, one small) at the western end of the pa. The only artificial defence recorded was a small terrace on the southern edge of the ridge, but the lack of any further artificial defences such as a ditch and bank is not uncommon for pa in the East Coast region; a number of pa are defined by groupings of pits and terraces in naturally defended locations such as this.

Haparangi was revisited by archaeologist Kevin Jones in 1982, presumably 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 completed a new sketch plan of the site, indicating that the ridge top consisted of two large terraces, with the shallow depressions recorded by the Gisborne Museum depicted as 'eroded pits?' He also recorded an additional terrace along the southern edge of the site.

In 2000, Haparangi was revisited by archaeologist Vanessa Tanner as part of the New Zealand Archaeological Association Site Recording Scheme Upgrade Project. The pa was covered in two metre high weeds at the time of the visit, but was still in good condition. A further site visit was undertaken in November 2007 by the New Zealand Historic Places Trust, by which time the gorse had been eradicated from the site. The gorse clearance may have caused some damage to the pa, and thistles had started to grow in places, but archaeological features such as the large pit at the western end were clearly visible.

Haparangi is one of several archaeological sites on the western bank of the Uawa River, near its confluence with the Waimanu Stream, which are of cultural, traditional and spiritual significance to Te Aitanga a Hauiti, and have been registered as a wahi tapu area. Haparangi also forms part of a much wider archaeological and cultural landscape that reflects the intensive Maori occupation and settlement of the Tolaga Bay area since the 14th - 15th centuries AD.