Praia Barril is a very large beach near the charming town of Tavira and only a few minutes by car from Cabana Branca. Just take the N125 road towards Tavira and turn to Pedras del Rei. There is a parking near the Ria Formosa. Then you have the choice, either walking towards the beach crossing the laguna (15minutes) or taking the small pittoresque beach train.
At the beginning there is a concentration of people, but just walk for a few minutes on the beach and you will be almost alone, even in summer. There is a nudist place a little bit further.
It is really pleasant to walk along this great beach especially when the tide is low.