Historical urban nucleus. City located on a hill. Village with war square and castle. Historical center integrating in a fortified system composed by two lines of walled fence and Castle, with two zones of distinctive morphological and typological characteristics that form the urban structure: Vila Velha (area of the Castle and Bairro de Santiago) and Vila Moderna. The urban structure has medieval characteristics, and from this time it was the definition of the current urban layout in the first extramural neighborhood (Bairro de Santiago).