Known as the Cathedral in the Fields, Hillesden’s church stands almost alone among the north Bucks farmland, a tall and elaborate Perpendicular building rebuilt around 1500. The stonework is unusually fine for such a small hamlet — a fan-vaulted porch and a stair turret finished with a little stone crown. It’s some way from anywhere, roughly ten miles south of Milton Keynes; opening is limited, so plan ahead.