Cracroft Caverns, also known as the Cashmere Caverns, are a series of large chambers in the hill of the Cashmere

Cashmere, New Zealand

The suburb of Cashmere rises above the southern end of the city of Christchurch in New Zealand’s South Island.-Geography:Cashmere is situated on the north side of the Port Hills, immediately above the southern terminus of Christchurch’s main street, Colombo Street...

 suburb of Christchurch

Christchurch

Christchurch is the largest city in the South Island of New Zealand, and the country's second-largest urban area after Auckland. It lies one third of the way down the South Island's east coast, just north of Banks Peninsula which itself, since 2006, lies within the formal limits of...

, New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

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Constructed secretly during the Second World War in response to the Japanese threat, they were intended to house operational headquarters in the event of attack. The military commandeered the Cracroft Wilson estate, founded by Sir John Cracroft Wilson in 1854, for their Southern Group headquarters, and work on the tunnels began in 1942.
Railways were built for access and for the removal of waste soil.