The atomic town that isn't on any maps: Manhattan Project's secretive site where 75,000 scientists and their families lived during race to create a nuclear bomb At its height in 1945, 75,000 people lived in the Tennessee town of Oak Ridge which was so secretive it didn't appear on any maps. The 59,000-acre town was created in 1942, as part of the Manhattan Project's race to build an atomic bomb. Within a few short years the weapons base had hundreds of miles of road and railway tracks, ten schools, seven theaters, and a host of shops and restaurants for the nuclear scientists working there. Top secret: A billboard in the nuclear research town Oak Ridge, which didn't feature on a map for years The government workers had been tasked with the research and production of nuclear materials but, as these Flickr pictures show, their top-secret base had the look of any other all-American town. A library, orchestra and sports facilities were laid on for employees of the gated community, where the average age of the residents was 27. In just over two years Oak Ridge became the fifth largest city in Tennessee and its residents benefited from fresh produce grown on site at a time of food shortages during the war. Today three of the four plants used to produce the material used in the first atomic bombs still stand, and trees planted during the Second World War flourish. The houses, which had been rented to workers for $35 a month, were sold to the public in 1949 - the first time the town appeared on a map - and a new community, with a current population of 28,000 now thrives there. Safety first: A fire truck is displayed during a safety week in the town that helped develop the atomic bomb Education: Pupils at Pine Valley School in 1945. Children of the researchers were taught in several schools in the town Sporting: The gated community offered tennis courts and other facilities to the scientists and their families Down time: A dance class at Oak Ridge in Tennessee where families at the secret facility were offered a host of activities Arms race: The 'Calutron Girls' at work in one of the uranium plants in 1944 Relaxed: Teenagers hang out at the town's recreation hall in 1945 while their parents worked on the atom bomb Family friendly: A sign warns motorists to watch out for playing children in the town in 1948 Homely: One of the apartments where staff stayed during their time in Oak Ridge Ordinary childhood: Youngsters read comics at a stand outside a boy's house in 1945 Community: Children board a school bus in 1968, after the government sold off its properties to the public Learning curve: Children pose by a firetruck wearing placards with safety messages in the 1940s Security: A billboard reminds residents not to talk about the project at Oak Ridge Show time: The recreation hall is packed for the town's Kiddy Club Fresh: During the war years the residents still had access to good food despite shortages elsewhere Atomic: At its peak years, 75,000 people lived in Oak Ridge, which was part of the Manhattan Project Site visit: The town's history has turned it into a tourist attraction Rite of passage: Members of the Oak Ridge high school basketball team have their initiation Off the grid: It covered 59,000 acres in Tennessee but Oak Ridge didn't appear on any maps until 1949 Research: A scientist at the microwave spectroscopy in Oak Ridge Cutting edge: A worker at the isotope storage area of the plant On call: Women prepare to swap shifts at the telephone switch board War effort: The nuclear research at Oak Ridge was part of efforts to win the Second World War