The Legend of Giant Causeway

Why do people have legends of giants all over the world? When it comes to giants that are really fantastically large, I think there are several factors. There's always someone who's above average, like in Lake Wopogon. You start wondering how tall could a person really get? And that leads people to imagine fantastically tall giants. Another contributing factor is natural geological formations around the world that look like they're built by humans.