It is an old stronghold in Ardebil state. In the past, castle has defended Iran against attacks of Rom legion. Oltan is a big village that located in 3 kilometers south of Pars Abad Moghan and oltan castle located within 500 meters of this village. It located in Moghan plain and on zero point border and sticking to Aras River. In the other hand Oltan was Iranian border camp in northwest. The appearance of castle induces the building of a fortress.

Ashkanian had built this castle about two thousand years ago, but because of strength and proper position it has used until twelfth century.

Unique and variable potteries have discovered in archeological excavations of this castle. Find Islamic coins in previous discoveries of archaeologists indicate that city was active in Islamic period.

Now, unfortunately, this caste is disappearing. This is down through a combination of two ways. First, for erosion of the beach of the Aras River. Gradually and due to rainfall, beach walls of the castle is destroying.

Two, for sand plant that located in front of this building. Factory workers by excavation for archive sand, are destroying all area of the castle. If the situation continues in this way, we can not find any sign from this historical heritage of thousands of years.

Now, the only way to prevention from destroying this historical monument is organisation and beach package of Aras river beach that located near this castle.

Oltan castle is located near the Aras River and in the neighbouring Oltan old village. This castle has built in 320000 square meter area. The appearance of castle induce the building of a fortress. This castle had built by Ashkanian in first and has used until twelfth century. According to the scientific speculations, the majority of the castle is buried under the soil. This ancient area was a city like most of the Iran old cities wich consist of various sectors, such as Sharestan enclosed section or Arg, outside section of Arg and the peripheral section of Arg which probably was considered as points of settlement and workshop. Approximately the area of this castle is 70 hectares. 33 hectares is Arg or Sharestan and 37 hectare is outside section and an ancient city named ‘Rabz’ or ‘Orsan’. This city was consist of two parts: military and residential.