The Blue Mosque is massive and was built in 1609. Inside is decorated with the famous blue Iznik tiles. All of the great mosques that grace the seven hills of Istanbul are alike in their gray stone construction and simple exteriors. In contrast, the interiors are covered with beautiful tiles and gold calligraphy and carpets. Our guide explained that the design difference in decoration is a reflection of the belief that it is what is inside that is important, the beauty and spirit of one’s soul is where the emphasis belongs.