Trewissick is a fictional seaside village, said, in Over Sea, Under Stone, to be 5 miles from St Austell in Cornwall. Trewissick also features as the main location in Greenwitch. If Trewissick was modelled on a real place, one possible candidate could be Mevagissey, which lies 6 miles to the South of St Austell and has a harbour. There is a local headland to the North, which is called Penare Point (Penare sounds a bit like Kemare), and another headland to the South, called Chapel Point. However, it is just as likely that Trewissick combines features from more than one location in Cornwall.