The Car Dyke is an eighty mile artificial water channel, thought to have been constructed by the Romans from the first century AD... The Dyke runs along the western edge of the fens from the River Cam near Cambridge all the way to the River Witham, just south of Lincoln. Many stretches are protected as a scheduled ancient monument... William Stukeley... came up with the idea that Car Dyke was a canal... to supply the Roman Armies of the north with grain and food from Lincolnshire and Cambridgeshire with drainage as a secondary function, a view which still perpetuates until...