Guardian: The Rough Guide to Wales describes Milford Haven as “one of the world’s greatest natural harbours”, and quotes lines from Shakespeare’s Cymbeline: “How far it is/To this same blessed Milford; and by the way/Tell me how Wales was made so happy as/To inherit such a haven.” The bard had a point – though since the late 1950s, such beauty has been rather sullied by the arrival of big industry: specifically, two massive oil refineries and an oil storage plant, serviced by a regular stream …