The 'Yıldırım Camii' is also called ‘Ulu Cami’ (Great Mosque), 'Karakadi Camii' (Mosque of the Black Judge) or 'Paşa Camii' (Mosque of the Pasha). Built in 1382, ordered by (the future sultan) Yıldırım Beyazıt, who was governor of the region at that time. The mosque has been restored several times, last after a severe earthquake in 1944. Fortunately, this didn’t alter its original appearance too much.
On the picture: The ‘mihrab’, restored in a 19th century style, influenced by European Neo-classicism.
Mihrab (Arabic: محراب miḥrāb, pl. محاريب maḥārīb) is 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."