Natural and human factors are always a threat to the destruction and damage of ancient monuments, and depending on the type of area, each of these factors can be damaging; many historical sites have been destroyed or seriously damaged as a result of these circumstances. Using GIS, the threatened regions of historical sites in Lorestan's Khorramabad region were identified to take action to preserve them. Shapur Khast Fortress (Falakol aflak), Broken Bridge, Safavid Bridge (Gap Bridge), brick minaret, Khorramabad inscription, and Gerdab Sangi are among the region's known ancient sites. Effective factors in the destruction of ancient monuments are five criteria defined by professionals in the field, which include the distance from the waterway, distance from the streets, slope, height, and slope orientation, all of which are depicted on a geographical map. The model is next assessed utilizing modeling by fuzzy logic operators approach and identifying the effect of each criterion. The final result includes five vulnerability classes: very high, high, medium, low, and very low. In this study, the AND operator provides the optimal risk-adjusted state, which has been proven by empirical verification and historical sources.