The 100 km are artificial and totally pointless ;-).
Quote [my translation]:
- This decision of the ecclesiastical entity [= Santiago Cathedral] is supported, according to the [Coruna] alderman, by "a historical and weighty justification." In particular, he points out that the port of Coruña was "the main point of entry for pilgrims, arriving from across the sea, from the fourteenth century onwards.
Today's caminos have little to do with the medieval pilgrimages but historically, a lot more - and I mean really a lot more - pilgrims started in the port of Coruna than in Ferrol or Sarria or Tui, ie than 100 km from Santiago.
The problem today is, of course, that you have to build and then row your own boat or hitch a lift on a sailboat if you want to arrive in the port of Coruna at the end of a sea voyage from your home country elsewhere in Europe or around the Med. There are no longer any feasible commercial options for passengers travelling to and from Coruna by ship, as it was the case in the Middle Ages. Perhaps this might change with this obvious promotion for starting in Coruna harbor - at least once in a while? I would be the first to walk from Santiago to Coruna and then sail home
.