Look for the mechanical rotating dervish statue on the roundabout at the southern end of Cumhuriyet Caddesi and you'll see the Dönenler Cami directly across the road. Built in the 14th century and later used as a mevlevihane (home to a Mevlevi dervish group), it evokes a Seljuk past with its galleried semahane (hall where Sufi ceremonies are held), which features paintings of tall Mevlevi hats on the columns.
It was closed for a mammoth, long-overdue restoration when we were last in town that was planned to be finished by some stage in 2020.