Isfahan rugs are of an excellent quality, using soft kork wool (often with silk details or foundations) and a very tightly woven pile. The rugs woven in this city are perhaps the best and most valuable in the world as a whole. The most popular design is a central medallion surrounded by vines or flowers which are usually red, blue or indigo on an ivory background. Other popular design elements and motifs include vase, garden and tree of life designs, Shah Abbasi motifs, and pictorial pieces. The inspiration for the rugs’ design comes from traditional motifs and patterns, nature, poetry and the great poets, but also from the rich architectural history of the city; the famous mosque of Shah Lutf Allah being a particular muse for many of the rugs created in this great city.