All of those features which make up the classic look of a Cornish fishing village are magnified in the stunning little town of Port Isaac, 12 miles or so north of Padstow on the Atlantic coast. Its sea inlet is narrower, its sides are steeper, its streets tighter, its older buildings more charming, and its whole appearance is one of extreme attractiveness. It has a kind of impossibly quaint perfection. The only slight downside is that Port Isaac is so appealing that it was used as the location for a popular and rather fatuous TV series, Doc Martin, in which it became the fictitious Port Wenn, a theme which is…