The Biological and Climatic Factors and their Impact at Harim Castle, Northwest Syria

This research aims to study the factors affecting building stones (limestone) in Harim Castle in northwest Syria, which threaten to erode the archaeological features of the castle due to neglect for more than a decade amidst the Syrian war. It also explores the methods for protection and necessary treatment measures, including physical and chemical treatments, to halt the growing and increasing risk in the absence of international laws concerned with the protection of cultural heritage. Among the most dangerous factors in Harim Castle are biological factors, represented by various types of impacts. This research highlights highly dangerous factors that cause fragmentation and breaking of building stone surfaces, distortion of decorations including inscriptions, signs, and symbols, and erosion of the mortar layer (clay) between building stones, making them less cohesive. These factors include living organisms (bacteria and fungi), birds (swallows, wild pigeons, and bats), animals (rats and mice), insects (ants and cockroaches), and plant roots (wild fig and Capparis or spinosa, and climbing plants). The severity of these factors on building stones in Harim Castle is exacerbated by their interaction with other factors, such as climatic factors, particularly (temperature and humidity). These cause cracks and fissures in building walls due to summer contraction and winter swelling due to thermal differences and chemical reactions, particularly acids and salts due to excessive humidity in the castle, especially in recent times.