Hi Viv
Just back from 2 weeks in Arillas and I can also confirm that the south beach was easy to access, and most days there were never more than about 8 or 10 people at the "far end".
By contrast, access to the north beach was very difficult and after one day there we abandoned it in favour of the south beach which is the first time we have ever used this part of the beach but quite enjoyed it.
Steve