Gylfaginning is a key narrative in the Prose Edda, a foundational text of Norse mythology written by Snorri Sturluson in the 13th century. The title translates to "The Deluding of Gylfi," and it tells the story of a Swedish king named Gylfi who seeks wisdom. He travels to Asgard, the realm of the gods, where he encounters three figures who reveal the secrets of the cosmos and the fate of the gods. The text explores various myths, including the creation of the world, the lives of the gods like Odin, Thor, and Freyja, and the eventual destruction of the world in a cataclysmic event known as Ragnarök. Through a series of questions and answers, Gylfi learns about the nature of existence, the afterlife, and the intricate relationships among the gods and other beings in Norse mythology.