Ajab Shir county is located at the southwest of the province and according to the archeological data and considering the fact that most civilizations and cultures have been formed next to rivers and water, this county is not an exception to this rule. Qaleh Chay river, in truth, has been the vital lifeline of this county from millennia before Christ until now and the existence of caves and rocky shelters indicate that cavemen used to inhabit this area. Some of these have been identified and nationally registered, many are known but unregistered.
Additionally, there are archeological sites in this region that, according to archeological data, date back to the Chalcolithic period, out of which Gul Tapa, Sichan Tapa, Tikan Tapa and etc can be named. The Urartu inscription of Javan Qaleh, 8 kilometers from the city center, in the new Javan Qaleh town, is what can be referred to of the written history of Ajab Shir; which is a conquest journal of the Urartu king, Argishti I, within which a v called Arsita has been mentioned (about 753 BC). This inscription is important both from historical and regional terms and it also mentions the Qabrli of Yengejeh. The existence of five historical castles dating from Parthian and Sassanid to the post-Islamic era can be mentioned.
From the Islamic period, beautiful wooden mosques such as the Shirlu mosque of Ajabshir, Ghazi mosque of Shishavan and Hanafiyyah mosque of Gowaravan (the oldest wooden mosque dating back to the Ilkhanid dynasty) and Dizaj of Shishavan and Emamzadeh Ghasem with Seljuk-Ilkhanid origin alongside the cemeteries of the Safavid era of Shiraz, Zaviyeh, Qozlowjeh, and Dizaj Hasan Beig can be mentioned. All of these are but a small portion of the history of this county.