@simonhei The phrase "The Hills Have Eyes" is best known as a title of a 1977 horror film by Wes Craven and its 2006 remake. In these films, the hills are inhabited by savage, mutated people who watch and attack travelers. While the idea is fictional, it's meant to create a sense of fear and paranoia by suggesting that unseen dangers lurk in the environment. In reality, hills don't have eyes; the concept is used metaphorically in horror to suggest that mysterious or dangerous entities might be observing travelers from vantage points in the landscape.
