Near my hotel in the heart of town there was this türbe or grave monument, as so often people seemed to consider is a holy place, one could often see people pray at what must be a window to the under part (for as far as I know the upper part will often house a cenotaph, the actual burial place is in the lower part). A sign said this is the Sadredin Konevi. However, a mosque nearby had a note: Devriş Ağa Camii (mosque) ve Türbesi dating to 1129.