The Ria Formosa lagoon, located in the Algarve, in southern Portugal, is a system of barrier islands that communicates with the sea through six inlets. Five of these inlets are natural and have mobility characteristics. The sixth is an artificial inlet that was opened with the purpose of allowing easier access to the port of Faro.
Presently the main inlet of the system is the Faro-Olhão inlet, which was artificially opened. The process started in 1927 but only in 1952 were the engineering works completed and it assumed the present configuration.