Albert Park tunnels The Albert Park tunnels are found largely beneath Albert Park , in central Auckland , New Zealand . The tunnels were constructed as air raid shelter s during the Second World War . At the conclusion of the war they were sealed to prevent vandalism or misuse by the public , and as a protection against carbon dioxide build - up or tunnel collapse . Conception . New Zealand ' s involvement in the war had begun in 1939 , and with Axis naval activity occurring in New Zealand waters , domestic defence plans were necessary , with much capital being invested . Matters became urgent with the entry of Japan into the war in 1941 . A number of coastal defences were already in place throughout the country , with a concentration in Auckland , and Auckland City Council felt the need for air raid shelters in the central city , in preparation for Japanese attack . Work began in December 1941 , and by January 1942 , 16 300 feet of slit trenches had been dug around the city . Additional shelters were created in basements and old existing tunnels . Auckland city centre had a daytime population of 78 , 000 , but by April 1942 shelter capacity was only 20 , 000 . Furthermore , experience in Britain during the Blitz indicated that deep shelters provided greater protection . Due to its topography and central location , Albert Park – a communal facility built in the 1880s on the site of an 1840s army barracks , – was chosen as the site for a major construction . In 1942 a large complex of tunnels and shelters was established under the park , capable of sheltering 20 , 400 people . The tunnels were designed by city engineer James Tyler , and were estimated to cost £120 , 000 ( about £6 per head ) , with £90 , 000 of the cost met by the government . With planned shifts running twenty - four hours , the work was expected to take four to six months . Work began in February , and the digging was completed in August . Carpentry and plumbing , at additional cost , was added over the following two months . The tunnels were officially opened by Mayor John Allum in October 1942 . Construction and structure . There are more than 3 . 5 kilometres of tunnels , reaching from Constitution Hill to Wellesley Street , involving a network of shelters , sanitation facilities and first aid posts , all ventilated by air shafts , with a total of nine entrances . The tunnels run through sandstone and volcanic rock , and were mainly dug by hand by a team of 114 council workers , most of whom were middle - aged men who were unfit for war . The tunnels were lined with over 975 km of native New Zealand native timber , including Kauri , Heart Rimu , Larch and New Zealand Stringy Bark . A total of 315 people were involved with this project . The central , arched access tunnels were , , and ; the grid of accommodation galleries – totalling – were square and provided with wooden seating . The floors were covered with scoria . The tunnel complex , unlike many other air raid shelter complexes , does not have blast doors , but instead has baffles . The baffle is a block in a tunnel constructed from wood , lead and stone to absorb the shock wave in the event of a bomb blast . The small tunnels around them allowed passage and reduced the shock with the perpendicular reflections . In 1941 , baffles had been added to the twenty - year - old Parnell tunnel . A diesel engine from an old meatworks powered the ventailation fans and emergency lighting , as well as a loud - speaker system . Post - war history . The expected air raids did not eventuate , and with the tunnels unused , by the end of 1943 the timber supports were beginning to fail . By February 1945 , without the money to upgrade or convert the tunnels to other use , plans were made to fill them in . The tunnels were filled in with 8 . 8 million unfired clay blocks which were made by Crum Brick and Tile in New Lynn . It took 15 men a total of 12 months to complete the back - filling process and the entrances were sealed and buried by 18 April 1946 . Since then , a number of schemes have been proposed to make use of reopened tunnels . In the 1960s there were newspaper articles proposing ideas , and interest was renewed in the 1990s by two separate groups : a businessman seeking to open it as a tourism venture , and a group of architecture students with their lecturer who considered the tunnels might offer a solution to Auckland ’ s traffic problems . In 1996 , the city council signed a contract with tourism promotor William Reid , giving him permission to unseal the tunnels and perform an inspection , with a view to developing a tourist attraction . Related legislation was passed in 2001 . In 2005 , subsidence occurred within the park , due to the collapse of in - fill soil within the old ventilation shafts . Blocked entrances can be seen at the top of Victoria Street – hidden by a decorative wall – and the steel door present at the foot of Constitution Hill . Three other blocked entrances are located behind the Park ' s Gateway sculpture . As of June 2012 , two Auckland residents Bill Reid and Mark Howarth , are working on plans to have the first 25m of tunnel five excavated in order to create a museum depicting its history . However , Auckland council has advised no investigations have been carried out with regards to work required to reopen the tunnels .