The Pars museum was originally a pavilion in Bagh-i Nazar, a garden in Shiraz built under the Zand ruler Karim khan (reg. 1749-1779). The design of the garden followed the quadripartite or chahar bagh plan, with the pavilion situated at the center and four axial pools. In the 1930s, when the northern part of the Nazar garden was destroyed to make way for a street, the pavilion was renovated to serve as a museum.

Sources:

"Maghbareye Karim Khan Zand (Pars Museum)." Iranshahr Encyclopedia of Iranian Architectural History. http://iranshahrpedia.ir/arch/handle/10667/6007. [Accessed September 21, 2010]