The small sang-e murmur (marble) “Pearl Mosque” served as the private mosque for the royal harem.  Standing on the western side of Shahi Qila, Moti Masjid is one of the few buildings within the fort deviating from the overall north-south orientation of the complex, satisfying the liturgical requirement that the mihrab face Mecca.

(Sharon C. Smith, 6 November 2014)