The region of Lagos has had human occupancy since prehistory. Lagos’s military defences were probably built by the Romans and occupied by the Visigoths and the Moors.
The town of Lagos had a decisive role in the Portuguese Discoveries: from Lagos left in 1419 the caravels that discovered Madeira archipelago; in 1427 the discovery of the Azores archipelago and from here also left the ships that conquered Alcácer-Ceguer, Arzila and Tânger in Africa.
Around the year 1642, during the Portuguese Restoration War from Spain, the Castle defences were reinforced for the use of artillery. Many of them were destroyed again with the big earthquake of 1755.
Nowadays the Castle of Lagos does not maintain much of its initial construction, going through many changes over the years. Nevertheless, this important heritage, classified as National Monument, is very well preserved and still is one of the main references in Lagos.