Four massive piers divide the interior spaces. They bear the weight of the nine domes covering the prayer hall.
The restored decoration of the dome in front of the mihrab is in imperial Ottoman style (16th – 17th century). The technique is called ‘kalem işi’ (= work of the pen/paintbrush). It is inspired on the geometric or stylised ornamentations used by Ottoman calligraphers to illuminate books.

Correspondent: J.M.Criel, Antwerpen.
Source: ‘Islamic Architecture: Ottoman Turkey’ (Godfrey Goodwin) – London 1977