The stone building of the Old Saray, located on top of a hill, is the largest extant building in Old Jaffa. It was built in the 18th century on the remains of a crusader structure and was likely completed at the beginning of the 19th century by Muhammad Abu Nabbut as part of a large construction and renovation project in Jaffa.
The large building served as the government palace (saray) for the majority of the 19th century. The complex included, apart from the saray, a kishle (prison), a post office, a public hammam (bathhouse), and a small mosque. In the 1870's, the kishle was relocated in the northeast corner of the city, next to al-Mahmudiyya mosque. In 1897 the government seat itself was moved to a new building that was built just outside the walls, in front of the kishle.
After the construction of the monumental New Saray, the Old Saray was used as a factory, owned by the Damiani family, for the production of olive-oil soaps. After the 1948 War the building was used by several other factories until in 1961 when it was transformed into a museum for the Antiquities of Tel Aviv-Jaffa.
Sources:
Or, Even, Peder, Shimon and Shaham, Zvi. 1988. Midrakhon Yafo: Madrikh leSiyur Azmi. Tel Aviv: Israel Museum.
Petersen, Andrew. 2001. A Gazetteer of Buildings in Muslim Palestine: Part 1. Oxford: Oxford University Press, 173-174.
Regev, Ofer. 1999. Touring in Tel-Aviv Jaffa (Hebrew). Tel Aviv: Misrad ha-Bitahon - haHotsa'a la-Or; ha-Mo`atsah le-shimur mivnim ve-atare hityashvut; Hakhevra le-Haganat ha-Teva, 48.
Yanon, Ya`acov. 2001. Sviv Kikar ha-Shaon. Jerusalem: Yad Izhak Ben-Zvi, 61-65