Annwn is a concept from Welsh mythology, often described as an otherworldly realm or paradise. It is associated with the afterlife and is depicted as a place of abundance, beauty, and eternal youth. In some tales, it is ruled by the god Arawn, who governs the souls of the dead and oversees the land's mystical qualities. In literature, Annwn appears in various texts, including the Mabinogion, a collection of medieval Welsh stories. The realm is often portrayed as a place that can be accessed through magical means, highlighting its significance in the cultural understanding of life, death, and the supernatural in ancient Welsh beliefs.