Fungi play a very important role in the biodegradation of archaeological stones in Tell Basta open area, leading to their biodeterioration and loss. Therefore, it was necessary to preserve these archaeological stones, especially sandstone. The sandstone was analyzed and examined using X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM) for deteriorated fungal growth and compared with control. Deteriorated fungi isolated from sandstone, such as Curvularia. spp, A. niger, A. flavus, and A. terreus and their deterioration were studied. Plant extracts have been used to inhibit fungal growth because they are ecofriendly materials, harmless to the restorer, and economically inexpensive. This study presents a new method for inhibiting fungal growth on the surface of sandstone located at an open site in Egypt, using plant extracts. Fungal growth was inhibited using different concentrations of aqueous garlic extract (900 μg/μl, 630 μg/μl, 360 μg/μl, 180 μg/μl) and methanolic clove extract (500 μg/μl, 375 μg/μl, 250 μg/μl, 125 μg/μl). Measuring the MFC value of the aqueous extract of the garlic plant and the methanolic extract of the cloves to determine the lowest concentration showed no visible fungal growth, and detecting the purified active components against deteriorated fungal growth of cloves.