The outsides of buildings in Muslim Spain were plain, monotone and highly austere with no windows in the walls. On the lower floors there were just a few openings for ventilation purposes, while the upper floors often had ajimeces, balconies that jutted out from the facade and were closed off with latticework screens. According to the Official Alhambra Guidebook, those viewing such houses and palaces from the outside have little idea of the treasures that lie within. It would have been impossible for anyone walking through a town or village in al-Andalus who stopped to look at a house to guess the social or economic status of the family who lived there or even the size of the house, until they passed the threshold and discovered the inner splendour of the courtyard around which its living spaces were arranged. In the Arab world the door is the frontier between the public and private. The door is not however a barrier. It is always open, although from the street it is impossible to see inside as the entrance is always organized in such a way that a partition, an elbow-bend or some other similar device protects the intimacy of the house, as can be seen in the houses in the Alcazaba and in the entrance to the Palace of Comares.