The Celts were a group of people who lived in Europe a very, very long time ago. They didn't have things like iPhones or cars like we do now, but they did have lots of legends and stories. Some of the stories were about their gods and goddesses, while others were about heroes who went on heroic adventures like going on a quest to find a magical sword or dragon and bringing it back home. The Celts also made and used lots of things made of iron, like swords and armour, and they built big stone walls around their villages to protect them. People still talk about the Celts today, and they are often used as characters in stories and movies.