Dutch film-maker Joshka Wessels spent two years making Tunnel Vision. She has recorded the revival in Syria of a system of underground irrigation that started to fall into disuse at the time of the Roman occupation. The qanats are a membrane of tunnels starting again to supply water to farmers in this arid country. In the Gulf its called the fallaj. It is believed the Persians invented the system almost three thousand years ago. A case of back to the future?