What is the myth of city of cydonia?

The myth of the city of Cydonia is based on the idea that there is an ancient and advanced civilization on Mars, specifically in the region known as Cydonia. Proponents of this myth point to the "Face on Mars" and other formations in the area as evidence of this lost civilization, though these claims have been widely dismissed by scientists and astronomers as pareidolia - the tendency to see familiar shapes in random patterns.