Falak-ol-Aflak Castle, Twelve Tower Castle, Kakh-e Atabakan, are the different names of Dež-e Shāpūr-Khwāst in Khorramabad. It is called Falak-ol-Aflak which means the sky of all the skies since the Qajar dynasty.
Being situated on the top of the hill, next to the river and on the Golestan spring, Falak-ol-Aflak castle is standing on the axis of Khorramabad. There are some historical monuments near this ancient castle, such as some prehistoric caves, inscriptions, brick minaret, Gabri water mill, Shapuri Bridge (Broken Bridge), and Gerdab-e Sangi (Gerdau Bardineh). This castle is registered on the Iranian National Heritage List.
During the Sassanid era, Shāpūr-Khwāst city was built near Khorramabad, and after its destruction, Khorramabad was constructed near its ruins. Falak-ol-Aflak was the capital of Hasanwayhids, Khorshidi dynasty, Ganjur, and Buyid dynasty from forth to thirteen century SH, and then it was the Treasury of Badr dynasty and also, it became a garrison and prison.
Being the headquarters of Division Five and other forces of the Iranian Army in the first half of the fourteenth century SH, this fortress was assigned to the Ministry of Culture and Art in 1349 SH. In the 1350s, this ancient fortress was changed to Anthropology Museum and Lorestan Bronze Museum. During these past years, Museum of Archaeology has been established in a section of this fortress in order to present the objects remained from Achaemenids and Kalmakarah cave, or to show twelve thousand pieces of Iranian history. Also, the reconstruction Lab and some other sections were opened there. This fortress is reconstructed many times.
Falak-ol-Aflak Castle is forty-meter-high and it covers one hundred and twenty meters. Its gate is located in the north of the castle and is three-meter-high and more than ten-meter width. It is made of clay, red brick, stone and mortar. Nearly a century ago, there was a rampart with twelve towers surrounding the main structure of the castle in the northwest. The form of this rampart is an irregular octagon.
This fortress has a twenty-three-meter rampart, eight towers, two central courtyards, and three hundred parapets, and it covers five thousand three hundred meters. Its rampart is made from Brick stone, clay, gypsum mortar, and lime. The Ports are installed in the north and the body of a tower in the south. After the port, there is a hallway that leads to the first courtyard (it covers one hundred and fifty-five meters and it has four towers).
The hallway of the second courtyard is located in the corner of the first one and it passes under an arch. The second rectangular courtyard has four towers and it covers six hundred and ten meters. In front of the hallway, there is another arch in which there is a forty meter well. This well is irrigated from Golestan spring. Near this well, there exists a bath.