Bergama prayer rug, late 19th century. The market at the top represents the mihrab as well as route of prayer. Even so, Saphs are not common. Their relative rarity tends to make them a really appealing sort for collectors. The example through the Nazmiyal Collection illustrated by this silk Yarkand http://prayermat96193.full-design.com/New-Step-by-Step-Map-For-Prayer-Rug-31454934