Kaiaua is a small coastal settlement on the Seabird Coast, on the western shore of the Firth of Thames, in the Hauraki District and Waikato region of New Zealand's North Island.

The Opita block was first investigated by the Native Land Court in 1869 following an application by Hamiora Te Rangituaatea of Ngāti Paoa in 1868.

The sale of the Opita block included an agreement to set aside and protect a ’burial ground’ near the mouth of the Hauarahi stream.

This prompted approaches by Pōkaitara Wikiriwhi of Ngāti Paoa to the Native Minister in the 1930s seeking protection.

[6] The Hauraki Rail Trail officially starts at Kaiaua and traces the coastline south along the Firth of Thames, over chenier shell banks and through wetlands of international significance.

It is one of the Great Rides of the New Zealand Cycle Trail system [7] The route incorporates a coastal bird watching area and Miranda Hot Springs.

Erected facing north east, the direction of prevailing winds, the sculpture symbolises the wildlife of The Firth of Thames.

They maintain a marae (tribal centre including a carved meeting house) called Wharekawa at Whakatīwai.

This is shared with the closely related people of Ngāti Whanaunga whose lands are located to the north of Kaiaua.

The ocean going ancestral vessel called Tainui travelled from central Polynesia and landed at Waihīhī, north of Kaiaua, in approximately 1350AD.