When I was researching the origin of the name Douarnenez I was particularly interested in whether it might be derived from the Breton: daou , ‘two’ [in Welsh: dau/dwy ] and Breton: (an) enez , ‘(the) island’ [Welsh: ynys ; Cornish: ennis/enys ; Irish: ennis ; Scottish: innis/inch ]. The second part of the name is the most obvious. This ancient place name element can refer to a peninsula (a 'quasi'-island) as well as a real island and this matched the topography of Douarnenez. The element Ynys/Ennis/Innis can be found in the names Anglesey/Ynys Mon, the Isle of Bardsey/Ynys Enlli, Enniskillen (N. Ireland) and Inchmarnock (Scotland). The daou/ 'two' element was pushing it a bit, but conceivably we could view the peninsula ( or even both 'banks') and the Isle of Tristram to the north as the two 'islands' in the name. If you are looking for myth it is interesting to note that another island may have existed off the coast at Douarnenez. Breton myt...