Function and Aesthetics. Screens, in a variety of patterns and for both functional and decorative purposes, are characteristic of Islamic architecture. The traditional domestic mashrabiya screens made of latticework, are common on windows in the Muslim Quarter, and in some houses in the Christian and Armenian Quarters of the Old City. The screens provide protection from the sun entering the rooms and allow ventilation and privacy in the interior. Decorative bay-window screens are a significant threedimensional architectural feature, in the overall picturesque character of the Old City’s urban scene.