Lagos is a city and municipality at the mouth of Bensafrim River and along the Atlantic Ocean, in the Barlavento region of the Algarve, in southern Portugal. The population of the municipality in 2011 was 31,049, in an area of 212.99 km2. The city of Lagos proper has a population of approximately 22,000. Typically, these numbers increase during the summer months, with the influx of visiting tourists and seasonal residents.