The mosque was being restored.

The Cumalıkızık mosque (reportedly) dates from the late 17th century, but was restored several times; last repairs happened in 1916 and 1950-55. The open gallery on the north side, where the congregation and visitors take off their shoes, is also the ‘son cemaat yeri’ (= ‘area for those who came late’), where worshippers who reached the mosque late or at the last moment, will gather and fulfill their prayer duty.
The fountain under the stairs had a double function: both civil (providing water to the neighbourhood) and religious (for the ritual ablutions).

Correspondent: J.M.Criel, Antwerpen.
Source: ‘Vakıf Abideler ve eski Eserler IV’ - Vakıflar Genel Müdürlüğü, Ankara 1986.