On the picture: The north (main) facade, and the mosque’s ‘avlu’ (courtyard) in front of it.
The structure on the right side of the picture is one out of three outside ‘şadırvan’ that belong to the mosque.

A şadırvan (from the Persian ‘Sadirvan’) is a type of fountain that is usually built in the yard or entrance in front of mosques or other buildings where ritual prayers can be held, with the main purpose of providing water for drinking or ritual ablutions to several people at the same time, but also as decorative visual or sound element.
It is a typical element of Ottoman architecture. It is also called ‘abdest alma çeşmesi’ (= fountain for ablutions).

Correspondent: J.M.Criel, Antwerpen.
Sources: ‘Vakıf Abideler ve eski Eserler III’ - Vakıflar Genel Müdürlüğü, Ankara 1983 & Wikipedia.