Maslak Pavilions
The first buildings in the area where Maslak Pavilions are located on the right of the main road connecting Levent and Ayazağa districts were built by Sultan II. It is known that it started during the reign of Mahmud (1808-1839) and that the region was used as a hunting and resting place for the sultans. Although it is not known exactly when and by whom the Maslak Pavilions were built, most of them date back to the period of Sultan Abdülaziz (1861-1876). During his years as a prince, Sultan II. Maslak Pavilions, which were allocated to Abdulhamid (1876-1909), witnessed the Sultan's invocation to the Ottoman throne, and in this respect, they are of special importance in terms of Ottoman history. Maslak Pavilions were used as a military preventorium (health institution where weak-bodied people who were infected with tuberculosis but not yet infected with tuberculosis were cared for to prevent them from contracting tuberculosis) between 1937 and 1982 during the Republican Era.
From Maslak Pavilions, located in a grove containing all shades of green in the middle of a 170-decare forest land, to the present day; Kasr-ı Hümâyûn, Mâbeyn-i Hümâyûn and Orangery, Çadır Pavilion and Pasha Office have survived. These buildings, integrated with the green cover around them, in a location with a good view of the point where the Bosphorus opens to the Black Sea, display outstanding examples of wooden Ottoman residential architecture and decoration of the late 19th century.
Today, Kasr-ı Hümâyûn has been repaired in the light of available documents, memories and old photographs and serves as a museum-house open to the public. Mâbeyn-i Hümâyûn and the connected Limonluk and Çadır Pavilion and its garden were also repaired with the same ideas, and there are cafeterias where visitors can sit and relax. The camellias that bloom in the orangery, especially during the winter months, offer a visual feast to their visitors. Maslak Pavilion gardens can also be allocated to national and international receptions.

Source Türkiye Culture Portal History of Istanbul