It is marked as "A Barca" on the IGN maps which are accessible online. It is near the river Miño and North West of Cortegada, more or less opposite Surreiro on the other side of the river. The
Concello de Cortegada has an
information page for A Barca online with a planning map where the hamlet of A Barca is one of the areas marked by red boundaries (I can't see place names on this planning map but it is easy to spot).
I don't know how close it is to any of the Caminos but since there are so many roads now being labelled as Camino there is probably one close by
.
PS: When you zoom closely enough into the area on Google Earth, you will see that there are a number of photos for A Barca and surroundings.