The artifacts discovered at this location show how a population once resided in the region now known as the Islamic Quarter, between the walls and the regions that surrounded them.

The Moors remained in this area until 1147, when Afonso Henriques, the first King of Portugal, took control of Sintra after capturing the cities of Lisbon and Santarém. Gualdim Pais, a master in the Knights Templar, was granted a charter in 1154 and was given strategic control over and responsibility for defending these domains over the town of Sintra and its immediate surroundings.The Islamic Quarter started to vanish once a Christian populace moved into the Moorish Castle, making way for a Medieval town whose occupation lasted until the 15th century.

As a result of the populace no longer feeling the need to seek shelter in the area of the fortification because the battles between the Moors and Christians had long since passed, the site was gradually susceptible to abandonment at that time. The Church of San Pedro de Penaferrim, constructed between the two rings of walls, was a feature of this medieval settlement. King Ferdinand II began restoration work on the castle early in the 19th century in keeping with the Romantic mood that was prevalent at the time, giving the medieval mythology that surrounded this location new life.