Although many of the older buildings outside the historical walls were demolished to make way for apartment blocks, the medieval quarter with its "Rua Direita" and "Rua de Santo António" have been declared historic zones. In these areas there are narrow multi-story dwellings, whose origin has been limited by the walled city. Historically, the old quarter was the city, and few buildings were located outside its walls, since its frontier location and the imminent risk of invasion impeded the construction of homes outside the barriers. Consequently, space was limited and land primarily used for multi-purpose dwellings, resulting in very narrow streets and multi-story structures (with balconies that extend over the streets and protected the citizenry). Many of the lower floors were occupied by shops or small businesses, while the residents lived in the upper stories. Remnants of these verandas are still visible in the medieval quarter.