The War Department halt was an informal railway station on the Romney, Hythe and Dymchurch Railway in Kent, England. Over the 15 years that the station was open, its location is believed to have moved several times. Details are scarce as this was a secret military installation, but the end of the War Department branch line moved as building work moved onto new stages. When the installation closed in 1945 the railway company took over the line for freight shipment of ballast. Again, the end point of the line changed several times as the exact location of extraction of ballast changed, until closure of the branch in 1951. The locations of the halt are now under water owing to subsequent commercial extractions and flooding of the ballast pits.