New Zealand Archaeological Association Site Record Number Z17/189 is a pit site that forms part of the dense archaeological landscape of the Tolaga Bay (Uawa) area. It is located on Titirangi Station, to the southeast of the Tolaga Bay township.

Pit sites and the many other recorded archaeological sites including pa, midden, gardens and urupa reflect the intensive Maori occupation of the Tolaga Bay 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.

Pit and pit/ terrace sites are very common in Tolaga Bay, and demonstrate the importance of horticulture to Tolaga Bay's earliest inhabitants. The Bay's fertile soils and temperate climate were well suited to kumara gardening, and the pits were used for storing harvested kumara over the winter months. Rectangular storage pits (which were once roofed with a layer of earth), are more prevalent than the underground storage pits found elsewhere in New Zealand, a pattern attributed to the harder substrate of the soil in this area. They are in fact the most common archaeological site type in Tolaga Bay, and are found along the river banks and on the rolling hills to the south of the Bay. They are generally located in clusters on knolls or terraces, or on ridge crests, in lines from end to end

Pit site Z17/189 is located on the level part of a prominent ridge to the south of the main Titirangi Station farm road, leading from the station yards to Cook's Cove. It is currently in pasture and native grasses.

This site 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. Z17/189 was recorded as a number of pits (some of which were raised rim) and a terrace. Jones completed a sketch plan of the site, showing two large raised rim pits at the north-eastern end of the ridge. A sizeable rectangular pit, 5 metre x 3 metre terrace and three small rectangular pits were located to the southwest, along the level part of the ridgeline.

Z17/189 was revisited by archaeologist Kate Hill in 1999 as part of the New Zealand Archaeological Association Site Recording Scheme Upgrade Project. Hill determined that Z17/189 was approximately 400m along the same ridgeline as Z17/188, and recorded two small terraces and three pits to the south, the southern- most pit measuring a substantial 5.5 metres x 3 metres x 1 metre (depth). Hill noted confusion between the two sites however due to erosion along the ridge, and the thick gorse cover at the time of the visit.

During a New Zealand Historic Places Trust site visit in 2007, features similar to those described and illustrated on the 1982 Site Record Form for Z17/189 were located on a levelled area of ridgeline to the northwest of the Z17/188. The pits and terraces were in average condition, with native grasses obscuring visibility in places. A subsequent inspection of a 2008 Google Earth aerial photograph however revealed pits further southwest along the ridgeline from Z17/188, which are more likely to represent Z17/189 given the site's location as shown on the Archaeological Site Land Title Form in Appendix 3.

Z17/189 is one of numerous pit and pit/terrace sites recorded in the Tolaga Bay area, and is part of a dense 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 AD, and the important role that horticulture played in this.