Notice on site: Firdevs Pasha mosque (also called Architect Sinan mosque). Built in 1561 by Firdevs Pasha, governor of Isparta, in the style of Architect Sinan during the reign of Suleiman the Magnificent. The square-planned and single domed mosque has a five-domed last congregation place (?) on the north and a minaret in the northwestern corner. On the north façade of the mosque there is a cross vault in the middle with a five-division last congregation place, which is covered with domes that have octagonal drums connected to each side with penditives. The roofing system is supported on the façade by pointed arches resting on six columns. The mosque has an entrance on the north side. The mosque has a foundation charter, which is dated 1565 (973 in Muslim calendar). It also takes place among the works of Architect SInan, for it is mentioned in Tezkiret-ül Bünyan, Tezkiret-ül Ebniye and Thuhfet-ül Mimarin (the sources that consist Sinan’s biography and works).
On the picture: The ‘mihrab’ (prayer niche).
Mihrab = a semicircular niche in the wall of a mosque that indicates the direction of the Kaaba in Mecca and hence the direction that Muslims should face when praying. The wall in which a mihrab appears is the "qibla wall."
Correspondent: J.M.Criel, Antwerpen.
Source: Wikipedia.