Emre Arolat’s 2012 design for the Sancaklar Mosque outside Istanbul challenges the Turkish capital’s ubiquitous soaring domes and patterned minarets. Instead, the firm built the 13,000-square-foot mosque into the side of a hill and clad it in natural stacked slate.  Photo 14 of 21 in I Love Modern Architecture from You Won't Believe That These Incredible Modern Buildings are Chapels and Synagogues