Ulu Mosque, one of the most beautiful examples of Seljuk architecture, was built by Kılıçarslan's son Rükneddin Mesud. On the inscription of the mosque, which was expanded and repaired during the Karamanoğulları Period, it is written, "The great Sultan Mehmed, the son of the late and regretful Ala-ed-din Bey, ordered it to be built and renovated in 811." name is written. In Ottoman records, the name of the mosque is mentioned as "Karamanoğlu Mehmed Bey Mosque".
The Ulu Mosque was built of smooth cut stone in a nearly square plan. The entrance is made through the crown door on the west facade, which is decorated with typical ornaments of the Anatolian Seljuk principalities. There are four feet in the direction of the qibla and three perpendicular to the qibla, a total of twelve. These feet are connected to each other by arches. It was made by Nüştekin'ül Cemali, one of the most famous wood-carving, mother-of-pearl inlay and pencil works of the period.
In addition, many carpets and rugs belonging to the Seljuk and Ottoman periods in the Ulu Mosque were taken under protection in the Aksaray Museum, and some of them were exhibited in the museum and presented to the visitors.

Source:

https://www.kulturportali.gov.tr/turkiye/aksaray/gezilecekyer/ulu-camii-karamanoglu-mehmed-bey-camii