Since historical buildings are living mirrors of the past, it is very important to preserve and transfer them to future generations. In this study, plants growing on the walls of Alanya Castle were identified and the damages that these plants gave to the historical construction and the precautions to be taken to prevent these damages were emphasized. A total of 94 plant taxa, including five pteridophytes, one gymnosperm and 88 angiosperms, belonging to 35 families were identified on the walls of Alanya Castle. Conyza canadensis, Inula heterolepis, Phagnalon graecum, Arabis verna, Mercurialis annua, Fumaria parviflora, Cymbalaria microcalyx, Galium canum subsp. antalyense, Parietaria judaica, Hyoscyamus aureus, Poa bulbosa were the dominant plant species of Alanya Castle walls. Possible seed dispersion of these plants on the castle walls and the methods for controlling them are discussed in detail. We conclude that the most effective method of combating plants that grow naturally on historical buildings and give damage to these buildings is mechanical excavation.