A decorative element of the vestibule that lies in front of the entrance to the prayer hall. It is representative of the carefully executed stonecraft in which the Sultan Beyazıt II mosque was erected. Classical Ottoman style, early 16th century. Note that the muqarnas used here were placed upside down.

Muqarnas is a stalactite-like decoration initiated in Anatolia by the Seljuk (in the 11th – 12th century). They imported it from Iran. Later on it continued to be used in the late-Seljuk architecture of the Beyliks (14th century) and by the Ottomans up to the 19th century.

Correspondent: J.M.Criel, Antwerpen.
Source: (amongst others) Wikipedia.