This is the "Evil Eye". It is a charm that is everywhere in Turkey. And when I say everywhere--I'm not exaggerating! It is cemented into concreted paths; hung on entrances, doors, windows, etc.; printed on clothes, built inside walls, printed on paintings, in jewelry, etc. The idea is that they will ward off any evil that might be around. Read more here, if you want.
There will surely be more pictures of this - I have a few more that I want to post. Does the evil eye exist in your culture?