One section of the mosque is called the Winter Mosque. This southwest iwan is flanked by rectangular rooms and halls are covered by eight domes and connect to two rectangular arcaded courts serving as madrasas. The domes are much lower in the height as compared to the other parts of the mosque.
The arch of the southern iwan rises to 28m in height and it is decorated with white, dark blue and light gold colours. Mehrab of Shah Mosque is inside the southern iwan, this section of the mosque finished in 1616. The interior of the dome is ornamented with the arabesque style and it sits at 53m in height.