On the picture: A ‘çeşme’ in an outer wall of the Hekimoğlu Ali Paşa complex. Late-Ottoman, ‘Turkish Rococo’ style, 18th century.
The calligraphic inscription are some verses of the 18th century poet Vehbizâde Münir.

A çeşme (a kind of fountain) is a piece of architecture which pours water into a basin to supply drinking water.
They were connected to springs or aqueducts. Until the late 19th century most ‘çeşme’ operated by gravity, and needed a source of water higher than the fountain, such as a reservoir or aqueduct, to make the water flow.

In addition to providing drinking water, fountains were used for decoration and to celebrate their builders, which were generally high state officials, whose name would be mentioned on the ‘kitâbe’ (= building inscription).

Correspondent: J.M.Criel, Antwerpen.
Sources: ‘Türkiye Tarihi Yerler Kılavuzu’ – M.Orhan Bayrak, Inkılâp Kitabevi, Istanbul, 1994 & Wikipedia.