The historical site of Belqis is located 3 kilometers south of the city of Esfarayen in North Khorasan Province. This site was registered in 2009 as a national heritage with the number 4497. The area currently identified as the Belqis site encompasses "Nārin Qale" and the present limits of the "Shārestān", totaling approximately 150 hectares. The restoration work carried out on the outer body of the western wall of Nārin Qale has been affected by rainfall, leading to erosion and damage. Whether the construction error of the restoration wall was the main factor causing this destruction is the question of this research. The aim of this research is to investigate the construction method of the structure and the role of this construction in the occurrence of damage. This applied research describes the damage conditions and analyzes the behavior of the restoration wall through field and library studies. The findings show that due to the construction error, the restoration wall has not been able to reliably direct and dissipate its weight towards the ground and ensure its stability. This study highlights a similar risk for the restoration wall that covers the entire outer body of the citadel fence as a protective layer.