Borazjan is a vast plain in the south of Iran, seventy kilometers north of Bushehr. It is spread over the center of Dashtestan County. This region is located between Shiraz and Bushehr, linking the two important cities from a long time ago. The road that goes through Shiraz, Borazjan and Bushehr are known as Rah-e Shahi or the royal road. This has turned Borazjan into a lively city with a long history and monuments such as Bardak Siah, Sang Siah, Charkhab that was once the winter castle of Cyrus. The remainings of Tal Khandagh that goes back to the Seleucid dynasty can be found in Borazjan, too.
The royal road that passed through Borazjan demanded caravanserais so that the travelers would have a safe place to rest. Haj Mirza Abolhasan Khan Moshir-ol-Molk, who was one of the elders of this land, and the ruler of Fars in 1350 SH, ordered for a caravanserai to be built in an area of over seven thousand square meters. The building itself id about four thousand and two hundred square meters. This caravanserai became known as Moshir-ol-Molk. It was built by Haj Mohammad Rahim Shirazi, who also built Moshir Bridge and Dalaki Caravanserai.
Moshir-ol-Molk Caravanserai is in the form of a rectangular. It has four towers and is more than twelve meters high. The towers provided safety for the people who rested inside the building. The materials used in this building are mostly stones and Sarooj, a type of water-resistant mortar, which makes it stronger in comparison with other buildings of its kind. In addition to the façade of the caravanserai that is covered with stones, the outside and inside of the entrance is covered with yellow carved stones. The entrance is located on the southern side, where there are three stories. The building is two-story on its other parts, and each story has two alcoves. There are two large and small yards in this caravanserai and sixty-eight rooms that have decreased and increased in number at different times.
Moshir-ol-Molk Caravanserai is a Qajar building located close to the main square of the Dashtestan, and has endured many years because of its strong structure. It was used as a resting area for only fifty years. From 1330 to 1365 SH it was used as commanding offices of the army. During the second Pahlavi era, it was used as a prison. Due to its warm and humid environment, this building could be used as a dreadful prison for political activists. That is why its name was changed from caravanserai into a fortress in 1336 SH. Borazjan Fortress was registered in 1362 SH as a national heritage of Iran. After long repairs and restorations, it became open to the public.