The main entrance, with the fine muquarnas in the top.

The building inscription above the door is written in decorative ‘sülüs’ script. It mentions sultan Beyazıt II as initiator of the külliye; Şehzade Ahmet, his oldest son and local governor at the time, was in charge of supervising the project.

(From Wikipedia): Sülüs (from Arabic: ثلث‎ ṯuluṯ "one-third"), also referred to as ‘thuluth’, is a script variety of Islamic calligraphy, invented in Persia and making its first appearance in the 11th century AD. The straight angular forms of the older Kufic script were replaced in the new script by curved and oblique lines. In Sülüs, one-third of each letter slopes, from which the name (meaning "a third" in Arabic) comes. It is a large and elegant, cursive script, used in medieval times on mosque decorations.

Correspondent: J.M.Criel, Antwerpen.
Sources: ‘Vakıf Abideler ve eski Eserler’ - Vakıflar Genel Müdürlüğü, Ankara 1983
& Website of ‘filozof.net’.