The red Phone Box seen in Local Hero was a movie prop put up because the actual phone box was not in a good position for the cinematography. It's location was in someone's drying area near the harbour.
However, many people make the journey to Pennan to have their photographs taken next to the actual phone box in the village. This is approx 20 yards away opposite a small, blue, badly worn, plaque commemorating the making of Local Hero.
The hotel seen in the movie is also fake, the buildings used for the hotel exterior were houses. The village shop exterior was a house near the harbour.