It is the largest Mosque of the West: is located on 30.000 m² of land and can accommodate up to 12.000 worshipers. It was commissioned and funded by King Faisal of Saudi Arabia, the founder of the Saudi royal family. As we read on the outside epigraph, its construction took more than two decades. In the structure, highly integrated the green surroundings, affecting the mix of modern thought and traditional curved lines. The large prayer room recalls a forest, with its columns and three stems. The use of light creates a meditative atmosphere. The use of materials and colors is a reminder of typical Roman: travertine floors and pink. The decoration, very discreet breadth of space, consists of glazed ceramics of delicate colors. The Koranic theme repeated is "God is light".