It is not an Island, it is in fact a Peninsula.
Locally known as Faro Island, it is actually a peninsula called “Ancão peninsula“. Located at the westernmost part of the Ria Formosa, it’s part of the barrier island system that protects the lagoon from the Atlantic Ocean. This peninsula spans from Ancão beach next to Quinta do Lago to Faro beach and is about 10km long with a width varying between 20 to more or less 100m.
Between the northwesternmost section of the peninsula and the urbanized zone, the dune string (height over 10m) has been interrupted by the remains of overwashes, some of which are over 35m wide, and by blow-outs caused by trampling, due to the disordered human occupation. The urbanized zone, known by locals as “Ilha de Faro” or Faro beach, is situated at the central part of the Ancão’s Peninsula. Here, people use the beach on the lagoon side mostly for fishing and molusc farming, occasional clam picking and watersports, while on the seaside, the beach is a bathing area with lifeguards on duty in the summer holiday season.
At Faro beach, due to the disorderly construction of houses, mostly clandestine at the ends, the sand dune has been largely destroyed and narrowing down each year. Because of this, the ocean overwash, which is a normal response to the sea level rise, and a common process that helps the migration of barrier islands, as became more and more frequent, but in this case, the barrier island is not moving at all.
You can reach Faro beach using the local ferry or going on a boat tour departing from Faro Old Town. This beach may also be visited by car using the only existing drive over bridge in the Ria Formosa, be advised that wild motorhome camping at Faro beach is forbidden, like in the all of Portugal and most definitely in the Algarve, you can be fined by the local police.
Barrinha or “The Sun’s Edge” is the natural inlet that occurs between Ancão’s peninsula and Barreta island which is the barrier island further to the West of the Ria Formosa, also known as Deserta island.
This tidal inlet tends to migrate from west to east, to a boundary position further away than its current location. The migration of this tidal inlet was very slight from 1966 to the bigining of this century and it is highly likely that, without the human intervention in the system, this tidal inlet would have naturaly closed further East and a new one would have opened on the west side of the peninsula, near Quinta do Lago. In the past 20 years, this natural inlet had 2 major interventions in order to increase water flow and oxigenation at the far West end of the lagoon system.