The door knockers of Artuklu Palace, which united the figures of a double dragon, a lion and a snake, are known, along with the whole structure of the 4 meters door where they were attached, through the descriptions made by the designer al-Jazari in his manuscript and the drawings within, Al-Jazari praises his door knocker as "a real masterpiece, a real pearl" and the door of the palace in the following words: "... then I made the rings as they embraced each other and their heads were turned to each other for each wings of the door.