One of the most important elements constituting the initial core of each ancient city is its military castle or fortress. The fortress of each city is usually where the king or rulers reside. Shushtar was of utmost importance as the capital of Khuzestan Povince due to its historical values.
The Salasel Castle is one of the other historical monuments of Shushtar which is in fact a large fortification belonging to Sassanid era. In the past, this castle consisted of large courtyards, military installations, bathrooms, bridges, and a garrison and a trench was dug in its surroundings, which has been partly ruined throughout the course of history.
Salasel Fortress is located on a hill overlooking Shatit River in the city of Shushtar. In pre-Islamic times water from the river passed beneath the Fortress and was redirected into different parts of the city. The Fortress was in use until the Qajar period (1785-1925) as a center for managing the water of the river. The exact date of the construction of the Fortress is unknown but it was possibly built during the Parthian or the Sassanid era (224-651CE). Existence of Parthian clays in the area is strong proof to this claim. Some experts date the foundation of the Fortress to the Achaemenid era (c. 550–330 BC).
One of the other features of the group of waterfalls and watermills of the city of Shushtar is their adjacency to the historical district of the city.In addition to the industrial uses of this water complex, it provided the water consumed by residents, in case of reduction of rainfalls.
One of the unique aspects of this water complex is that the water used by watermills later forms man-made waterfalls which pour into a pond, creating a spectacular scene that captures the attention of every viewer. Also, the dug tunnels behind the dam have created a scenic landscape. These tunnels transfer a certain volume of water to revolve the wheels of the watermills.
Archeological boring pits in the southern shell of Salasel Fortress in the city of Shushtar in Khuzestan Province resulted in the discovery of an Islamic graveyard belonging to the middle Islamic period (1050-1450 AH). The boring pits were dug at distances ranging from 120 to 130 meters from the Fortress. The design of a flying bird, four swords and daggers and a shield was carved on one of the graves of this cemetery. The designs on the graves are believed to be the symbols of death and ascending to God.
Salasel Fortress has largely been devastated due to several conflicts that occurred in the region as well as natural disasters such as flood and earthquake. Yet it remains a precious source of information for archeologists who have thus far found numerous historic evidences in this ancient fortress.
The fact of the matter is that this engineering complex is rather unique worldwide.Iran’s Cultural Heritage and Tourism Organization has recently been granted the ownership of this Sassanid Fort, a very welcome move as for years Salasel Fortress has been utilized as a storage area for keeping goods by different organizations.
For many years this Sassanid Fortress did not have any legal custodian and therefore was not well preserved. The activities of these organizations, especially the restoration work done without consulting experts in renovation of ancient monuments, have greatly altered the historic architectural style of this Fortress.
This castle as well as other 15 monuments of Shushtar was registered in UNESCO World Heritage as the tenth Iranian monument on June, 26, 2009 by fulfilling criteria 1, 2, and 5 under the name of Shushtar Historical Hydraulic System and under the registration number of 1315.