Borough Hill, Daventry

Borough Hill is Daventry's grassy plateau with a serious backstory: one of England's largest Iron Age hillforts, later the BBC's world-service transmitter station, and the site where Watson-Watt first proved radar worked in 1935. Today it's a free country park run by West Northamptonshire Council with close-cropped grass and huge views over the county's uplands — a rare asset in a county whose obvious water features, Pitsford and the reservoirs, are off-limits for TOAL under Anglian Water rules. The council publishes no drone prohibition for the site, so considerate hobby flying is workable: launch away from the car park and the steady procession of dog walkers, and give the remaining Arqiva communications mast a generous margin, because its guy wires are nearly invisible against the sky and it's the tallest structure for miles. The hillfort ramparts read beautifully in low raking light, especially under frost or after mowing, and sunset over Daventry with the Warwickshire ridge behind is reliable. Coventry Airport is about 25 km north-west and Sywell's FRZ roughly 25 km east — both comfortably clear. It's a scheduled monument, so keep everything airborne and leave no trace: no pegging landing mats into the ramparts.