A replica World War II underground bunker is being opened in Oxfordshire telling the story of a group of secret specially trained fighters. The original site in Coleshill was used as a base to train Auxiliers to undertake guerrilla warfare in the event of an invasion. About 3,000 men were recruited and secretly trained there in a series of underground bunkers. The buildings are now looked after by the National Trust. Archaeologists have unearthed a number of military sites on the Coleshill estate. The old bunker and the new replica are on private land and only occasionally open to the public. But visitors to the village can learn about the training facility at any time by visiting a renovated guard house which contains displays and recordings from former residents talking about their time there during the war. The National Trust has used Heritage Lottery funding to recreate the original bunker on the site, which was a prototype for similar units to be built all over the county by the Auxiliers. The replica is made to the same specification and will be used for prearranged educational visits and special guided tours ensuring the original structure is not damaged. The site will be transported back to the 1940s over the weekend for the opening, which will involve surviving Auxiliar Bob Millard, 89. Mr Millard was 17 when he arrived at Coleshill for his training and did not talk about his experiences, or even tell his wife, for 50 years. He said: "Our training was intense and very, very thorough. We were trained to kill…you could say, I was not a very nice person by the time I finished at Coleshill. "My job was to stay underground behind German lines and then emerge to interrupt transport to delay the invading forces. Blow up railway lines, blow up supplies, blow up petrol tanks, that sort of thing." Mr Millard was recruited from the Home Guard and asked if he would like to join something more exciting. He remained an Auxiliar from September 1940 until 1942 when he signed up for the Fleet Air Arm. see video:BBC News - Coleshill World War II bunker tells story of Auxiliers