The Sadabad Mosque, also known as Çağlayan Mosque and Aziziye Mosque, is the first mosque built in the Sadabad recreational area, along with the Sadabad Palace, in the year 1722 during the Tulip Period.
The original mosque was destroyed during the Patrona Halil Rebellion and was subsequently repaired twice, during the reigns of Sultan Selim III and Mahmud II. In 1863, upon the order of Sultan Abdulaziz, the Balyan brothers, Sarkis and Agop, redesigned and rebuilt the ruined structure, and the mosque has survived to the present day.
The mosque’s mass, with its symmetrical plan, consists of the prayer hall (harim section), the imperial lodge located north of this section, the residential areas, and the minaret on the western facade. Above the mosque entrance, there is Sultan Abdulaziz’s signature from 1863. Below the signature, there is a ten-line historical poem written by Ser Kenan Abdülfettah Efendi in his calligraphy, along with a ten-line date poem by the poet Kamil. The mosque, built in the Western-influenced architectural style of the period, rises on orderly-cut stone walls with double rows of windows. It has a square plan with a wooden dome above the prayer hall. The interior of the lead-covered dome is decorated with floral patterns. The sections outside the prayer hall are covered with sloping roofs. Only the decorations in the mihrab (prayer niche) and the remaining mihrab tiles on the walls have survived.
The small minaret, made of cut stone, has unsurfaced surfaces for its base and shaft. The minaret, designed in the Neo-Gothic style, contains two separate staircases, each consisting of 96 stone steps. One staircase can be accessed from inside the mosque, while the other can be accessed from the garden. Two people can ascend to the balcony without seeing each other at the same time.