Church of San Sebastian is located on a hilltop, near the fish market, in the northern part of the old city of Lagos. From this location offers stunning panoramic views of the bay. The church is considered one of the oldest and most beautiful churches in the city.

Even before the church was built on this spot in 1325 was a chapel of the Immaculate Conception of the Blessed Virgin Mary. In 1463, Bishop João de Mello has done that in this place a church was built. In 1490, by order of the King of Portugal, Don João II, we were again conducted reconstruction work, and the church was extended. After that, the church was consecrated as the Church of San Sebastian (Church of Saint Sebastian). Unfortunately, as has happened with many historical buildings in Portugal, the church was virtually destroyed during the Lisbon earthquake in 1755. The church was restored, and two centuries later, the church was again destroyed by an earthquake that occurred in 1969. Over time, the church was again restored.

Inside the church of three naves separated by Doric columns. The original main altar of the church dates back to the XVI century. Altar consists of four panels. It is expected that these panels created one of the most famous artists of the Algarve in the XVI century Alvaro Dias. The church kept the old plan of the city. In 1828, the church has a tower with a bell.

In 1924, the church of San Sebastian has been listed as a monument of national importance.