Spectacular pā and other archaeological sites survive throughout the island, evidence of its long Māori history. Māori named the island Aotea (white cloud).
When Europeans arrived, they found a rich bounty of resources to exploit: whales which migrated along the coast were hunted for their meat and oil; copper, gold, and silver ore were mined from the island's rocks; the huge kauri trees which covered the island were felled for their superb timber and then raided for their valuable gum; other trees were logged for the firewood trade. Relics of all these exploitive industries can be seen today, including impressive timber dams once used to drive kauri logs down the Kaiarara River.
Aotea is an important place in Māori traditional history. The Ngāti Rehua, hapu of Ngāti Wai, who live on the island today can trace their association back over many centuries. Evidence of this long history are the island's numerous archaeological sites, generally occurring in coastal locations. They include pa (earthwork fortifications) with extensive defensive and habitation features; agricultural and settlement sites identifiable by their still visible terracing, storage pit depressions and deposits of food waste ('midden'); and stone-working sites. Some of the midden have been dated to the earliest period of occupation, and provide information on the past environment and food sources.
Copper was discovered at Miners Head in 1841 and New Zealand's earliest mine workings were established there in 1842.
The main chamber of the coppermine is 75 m long, 25 m wide and 50 m high.
Gold and silver were discovered in the 1890s and numerous shafts and adits are located in the Okupu/Whangaparapara area and elsewhere. Remains of the 1899 Oreville stamping (ore crushing) battery at Whangaparapara, with its massive stone walls above and below the road, are an impressive reminder of the gold and silver mining era.
The timber industry also brought great changes to the island. The native forests were largely intact until the 1840s and the arrival of the Europeans, but were logged with increasing intensity from the mid 19th to the mid 20th century. A few areas of original kauri forest survived, and a large part of the remainder has since regenerated and is protected in public ownership by the Department of Conservation. The NZ Forest Service planted approximately 150,000 kauri seedlings between 1976-1987.
One of the island's best known historic landmarks was the Kaiaraara main dam (the "Lower Kauri Dam") on the Kaiaraara Stream below Hirakimata (Mt Hobson). Built in 1926 by George Murray of the Kauri Timber Company, its dimensions are impressive (40 m wide by 14 m high, one of the largest of c.3000 timber dams built in New Zealand). Kauri driving dams were built by loggers to drive large quantities of kauri downstream.
Built without the aid of drawings or engineering calculations, they provided a barrier against many tonnes of water and considerable quantities of kauri logs and were able to withstand the combined force of these when the dam was tripped and the logs were driven downstream through the gate.
The Kaiarara main dam was a type known as a 'rafter flume dam'. Rather than having a solid gate it was built with loose gate planks which hung vertically - a concept thought to be unique to New Zealand. The dam was destroyed in a storm in 2014 but the base of the dam can still be seen in the stream on the Kaiaraara track.
Another reminder of the logging days is the ruins of the early 20th century Kauri Timber Company milling operation at Whangaparapara. The remains include a steam tractor, cast iron chimney stack, concrete pads and stone walls. This was once a very large sawmill which processed logs rafted by sea from the Coromandel and Northland as well as from the island. Some of the walking track routes in this area follow the early tramlines used by the logging industry.
The Tramline Track is the most impressive. In its day (1925-4) it was one of the most extensive incline systems in the world.
The remains of the last whaling station to be established in New Zealand can also be seen at Whangaparapara. Whaling began in New Zealand waters in the 1790s. The peak year for whaling was 1839, with 150 American whaling ships and 50 from other nations recorded in and around New Zealand waters. Depletion of whaling stocks and a more enlightened approach towards marine mammals has led to the banning of whaling in New Zealand's waters. The Whangaparapara station, built as recently as 1955, had closed by 1962.
The Harataonga Homestead (c.1906), managed by the Department of Conservation but privately leased, is one of a few surviving early homesteads on the island. Nearby is a small cemetery where members of the Alcock family, one of the early European settler families on the island, are buried. A headstone to a Dr Hanson is a bit of an anomaly.
Dr Hanson, the black sheep of a well-to-do family in England, worked at the mining camp and is said to be buried above the Oreville stamping battery, his workmates having drunk away the money sent by his family to provide for his burial. When a headstone arrived from England some months later it was set up in the Alcock cemetery for convenience.
A number of ships have been wrecked on Great Barrier's rugged coastline.
SS Wairarapa is the most famous. The ship struck the rocks near Miners Head at 8 minutes past midnight on 29 October 1894. About 140 were drowned, making it one of the worst shipwrecks in New Zealand's maritime history.
The remote location of Great Barrier and the island's distance from the mainland made the job of rescuing the survivors difficult. Most of the dead were brought back to Auckland, but some remain buried on the island in two small cemeteries which can be visited at Onepoto and Tapuwai historic reserves.