From the web I gathered: "Located at the junction of Abdal Street, Tahal Street and Gül Avenue, the mosque was built by Başçı Ibrahim Efendi in remembrance of Abdal Mehmed, who was a well-known Sufi of the Murad II. era. On top of the rectangular-planned mosque, there are two oval domes. Next to the mosque are a tomb and a water fountain. The mosque has largely been repaired by the Bursa Association of Antique Lovers in 1955."

How the mosque came into being is an interesting story:
Başçı Ibrahim Efendi had been the favourite pupil of the Sufi-master Abdal Mehmed, and it was told that he was blessed with great wealth after his master had said a special prayer in that intention. Başçı Ibrahim used his wealth to commission a number of public buildings, including two mosques, a hamam, a graveyard and a mausoleum for himself. In building the mosque in remembrance of Abdal Mehmed, he shared (in some way) his opulence with his former teacher – what the latter surely would have refused, if he had still been alive…

On the picture: The large porch of the mosque (8 x 4,7 m). The presence of a smaller mihrab (prayer niche) makes it obvious that this 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.
In the back: the shoe racks, where worshippers and visitors leave their shoes (since they must take them off when entering the mosque).

Correspondent: J.M.Criel, Antwerpen.
Source: ‘Vakıf Abideler ve eski Eserler (volume III)’ - Vakıflar Genel Müdürlüğü, Ankara 1983