In pre-European times the island was occupied by Maori, and contains several Māori archaeological sites (M04/172, 174, 175, 176, 177). Cape Maria van Diemen was named by Abel Tasman in 1643 in honour of the wife of the Governor of Batavia. Following the European settlement of New Zealand, shipwrecks became a concern for mariners and settlers alike. Helen Beaglehole has outlined the growing concern and the various official reports in the 1850s and 1860s that lead to the belief that the creation of a network of coastal lighthouses was required to ensure the safety of shipping around what is, in many places, a treacherous coastline. The creation of the Marine Board in 1862 gave impetus to this development, and a number of lights were erected, in Cook Strait, in the South Island, and in the North at Tiritiri Matangi. The erection of a light at Cape Maria van Diemen, as well as one at Cape Reinga, was recommended by the 1854 Beacons and Lighthouses Committee and by the Marine Board in 1863-5. An alternative suggestion was made in 1873 that the northern light should be erected at North Cape. A series of comprehensive coastal surveys were undertaken by the Marine Department's acting Secretary Robert Johnson and its new Marine Engineer John Blackett. Johnson and Blackett identified Motuopao Island off Cape Maria van Diemen as a suitable location in preference to Cape Reinga or North Cape, since it had a wider arc of visibility and easier access by water. As with a number of other land acquisitions for lighthouses, the Government acquired the land by extinguishing the title of its Maori owners and ordered the lantern and light apparatus from the United Kingdom. The apparatus, including an eight-panel Fresnel lens system, made in France, was then shipped to New Zealand on the Arari in 1876. A work party began construction in August 1877, materials being landed on the beach from the Government steamer Stella. A derrick was erected for hoisting equipment ashore and a tramway laid up the island's central valley. The lighthouse was designed by John Blackett and was identical to one erected at Centre Island in Foveaux Strait the year before. The Motuopao lighthouse was formally illuminated on 24 March 1879, the sweeping beam being visible from a distance of 40 kilometres. A fixed red sector was displayed from the lower part of the tower to warn of the dangers of Columbia Reef. Total construction costs were ₤7028.14.8. The first principal keeper was John Wheeler, with assistants Robert Wilson and Charles Gibbons. The first mail service was provided by Samuel Yates from Parengarenga, but this was dependant on fine weather for the keepers to cross the channel in their whaleboat to meet the rider. Apart from periodic supply visits by the Government steamers, this mail call was for nearly twenty years the island's only contact with the outside world. An aerial ropeway was built in 1886 in a bid to improve deliveries of mail and fresh meat. A wire rope was stretched across the channel. Attached to the main cable was a hauling wire with a big wicker coal basket attached. The basket had to be wound across and back by hand. Salt spray and storm damage meant the cable had to be replaced on a number of occasions over the years. The Marine Department issued specific orders that the keepers were not to use the aerial conveyor for personal transport, though this order was not always obeyed. In 1895 the Post and Telegraph Department ran a wire 96 kilometres north from Awanui to connect the Lighthouse settlement to the telegraph system. The telephone exchange was attached to the principal keeper's house and included a small post office, one of the smallest in the country. Drifting sand was a constant problem, and the keepers were kept busy clearing sand away from the buildings and tramlines. In 1903 one of the cottages had to be replaced when it became unfit for habitation. During 1908 major improvements were made at the landing as storm damage there had been considerable. A new landing terminal was blasted out of the rock face and the tramway re-routed along a higher cliffside cutting. The early houses were located on sandy terraces up the northern slope of the island below the tower, with the principal keeper's house nearest the summit. The assistants' cottages lower down were subject to the worst sand drifts and in 1921 two new houses were built on firmer ground across the valley, on the southern hill. In dense fog, a lighthouse was not very effective. Experimentation with radio beacons was begun by the Marine Department in 1922, when an experimental radio beacon was estab¬lished at Cape Maria van Diemen Lighthouse, because of concern about the possibility of further wrecks on the Three Kings. The beacon would only be effective if ship owners put receivers on their ships, and there was initial reluctance to do this. However, the Marine Department decided to proceed and a permanent beacon was installed in 1926. In the first three month period, fog caused the beacon to be used 26 times, transmitting for a total of 169 hours. This was the first radio beacon to operate in the Southern Hemisphere. In 1937 various proposals were investi¬gated to modernise the station. These included the provision of electric power and the installation of a new wireless beacon. The isolation of the lighthouse and the welfare of the three families was a constant source of anxiety to the Marine Department, since the dangerous boat landing made the place difficult to service. Options considered included construction of a causeway or suspension bridge, but both were considered impracticable. Conse¬quently the decision was taken to build a new lighthouse on Cape Reinga, on a site to which a road could be built. This was the same place that Johnson and Blackett had rejected in 1874. The last official date stamp at the Cape Maria Post Office was recorded on 6 October 1940, though the telephone link remained in operation for another month. The lighthouse was extin¬guished for the last time, by Assistant Keeper Bill Tait, on the morning of 2 November 1940. The lenses and machinery were dismantled and shipped down the coast to the Bay of Islands, then trucked north to Cape Reinga, only 7 km from the original site. A small automatic beacon was operating at Cape Reinga the same day that the Cape Maria van Diemen Lighthouse was extinguished, but the original equipment was not exhibited from the new site until 3 October 1941. In 1943 an automatic flasher was placed on the mainland at Cape Maria to mark the sector down the west coast which is obscured from Cape Reinga. When the lighthouse closed, everything salvageable was removed from the island, though all the buildings, including the lighthouse, were abandoned on site. In 1950 the three surplus cottages, nine stores and other outbuildings were sold to a Whangarei buyer. The wooden tower was retained to protect a survey trig. A working party dismantled everything except the old principal keeper's house and the kerosene store which were not economic to salvage. The island had been designated as a lighthouse reserve when it was taken from its former Māori owners. In 1962, the reserve classification was changed, to become a reserve for the preservation of flora and fauna. In 2001 the Department of Conservation undertook repairs to the framing and cladding to prevent further deterioration of the lighthouse tower. This was followed in 2002 with the placing of a temporary roof over the structure to exclude water.

Cape Maria van Diemen Lighthouse is an octagonal wooden tower built on the highest point of Motuopao Island to the west of Cape Maria van Diemen. The structure is now 6 metres high and measures approximately 4.5 metres in diameter at the base, tapering to approximately 4 metres at the top. Each of the eight faces is approximately 2 metres in width at the base. The lighthouse on Centre Island in Foveaux Strait (not registered) was built to an identical design. It still has its lantern intact and is said to be 12 metres high. Both Cape Maria van Diemen Lighthouse and Centre Island are listed by Beaglehole as being 20 feet [6 metres] high, which presumably refers only to the height of the tower. The door was in one of the eight sides, with a small square window opposite it. A third small opening was in one of the side walls was a port for a fixed red light bearing upon Columbia Reef. Access to the exterior of the lantern and the platform that surrounded it was by external iron ladder. This gave access to a platform around the perimeter of the structure, used to clean and maintain the glass and the lantern. The walkway comprised a series of timber brackets which supported timber framing. Timber planking was then fixed to the support structure, waterproofed with a bitumen-impregnated felt such as "Malthoid". The ladder is no longer on the site. Following the removal of the lantern, rainwater and sea spray was able to enter the structure though the open top. Work by the Department of Conservation in 2002 placed a temporary 'lid' on the tower to make it watertight again. Interior Form The interior comprised two rooms one above the other, linked by a stair. The lower room was the main work and storage area. The upper room housed the clockwork machinery that rotated the lamp, driven by weights on ropes that let down though a central port in the floor and into the well in the foundation. Construction The lighthouse is set on a concrete foundation wall. On top of this were two perimeter base plates, one 300 x 200 mm in size and the other 300 x 150 mm. These plates were bolted to the concrete foundation. A well in this foundation provide the necessary height for the weights for the clockwork mechanism that rotated the light. The main structural frame is believed to be Australian ironwood. Each corner comprises two 300 x 150 mm studs set into the bottom plate. Each wall frame also has a 300 x 150 mm plate at the top of the wall and one of a similar size at first floor level. Between each corner were fixed three intermediate studs at the lower level and two at the upper level. These studs are kauri and measure 125 x 100 mm in size. The studs are housed into diagonal cross bracing units, each element of which is 200 x 150 mm in size. Iron tie rods placed through the window openings, provided additional bracing. The ground floor framing comprises a series of 125 x 50 mm joists laid over bearers. The flooring is tongue and groove kauri measuring 150 x 40 mm. The upper floor framing consists of two large beams measuring 300 x 225 mm and which act as trimmer joists at either side of an opening above the weight box well below the ground floor and a series of smaller 300 x 75 joists. The flooring at this level is similar in size to that at the ground floor. Sheathing and Trim The external faces of the lighthouse were originally sheathed with shiplap kauri weatherboards. Some of this has been removed or has deteriorated since 1940. Work by the Department of Conservation in 2001 sheathed the exterior in plywood, covering but retaining the remaining the weatherboards to protect them from further deterioration. The interior surface of the weatherboards remains visible on the inside. At each corner are two facings which act as corner boxes. Joinery The door to the lighthouse is no longer on site. The drawings indicate that it was probably of framed and ledged construction and sheathed with tongue, grooved and veed boarding. Both of the windows have also disappeared. It is likely that they each consisted of a single sash with the glass possibly divided with glazing bars, as is the case at Centre Island. Condition of the Structure Because the structure was not water tight once the lantern was removed, deterioration occurred at a faster rate than would otherwise have been the case. For that reason, in 2001 and 2002 the Department of Conservation undertook a range of repairs recommended by Dave Pearson Architects, and designed by C.H.Hall, architect and Anthony Marino, engineer. These involved the use of plywood sheets to sheath the exposed portions of the tower, and a “lid” of plywood coated in Resene Alumastic High Build Epoxy. Wire rope and turnbuckles were installed in the interior to improve the structural strength of the structure and its ability to withstand the strong winds experienced in this isolated place. These repairs were carefully designed to interfere with remaining original fabric as little as possible. They are explicitly a short term preventative measure, until a longer term solution to the preservation of the lighthouse can be developed. Other Components of the Lighthouse Settlement The Cape Maria van Diemen Lighthouse settlement was a small community providing accommodation for the keepers and their families, storage for their equipment, means of communication and means to obtain supplies of both food and equipment. As well as the lighthouse, there was the Principal Keeper's and two Assistant Keepers' houses, a signal hut, workshop, a tramway winch, a library and kerosene store, a radio hut, boat shed, store and a concrete landing area with a derrick. Different elements of this settlement were erected, developed or removed at different times throughout the seventy years of the settlement's existence. The lighthouse tower is the only structure remaining relatively intact, although the remains of the keepers' houses and some other elements are still readily apparent. The houses are the most obvious from their brick chimneys and concrete footings, while steps or footings indicate the location of other buildings.