Googling for "Praia da Mariana" (Mariana's Beach) and similars does not provide much information in English, but there is some...
This page, for instance, tells of some "semi-exotic birds" and has a warning about the "crazed Viana locals"...
Now... I know I used to go to that beach when I was a kid, but that's all over now, so...
Location here (it's the red circle, in Afife), very lousy photo here
Surfin (Score:1)
I found a couple of places in/on Peniche, apparently ( so I've read ) they get pretty good surf down there too:
Re:Surfin (Score:1)
Yes they do. And check out Ericeira too, which can be found in this map [nomadsurfers.com].