Irish mythology, a vibrant body of indigenous myths, stands as the best-preserved branch of Celtic mythology. Passed down orally from prehistoric times, these compelling tales were eventually recorded by early medieval Christian scribes, who preserved and somewhat Christianized them. The myths are conventionally grouped into 'cycles,' notably the Mythological Cycle, which chronicles the god-like Tuatha Dé Danann—representing Ireland's pagan deities—and other mythical races. Central to these narratives are figures like The Dagda, The Morrígan, and Lugh, members of the immortal Tuatha Dé Danann, who reside in the Otherworld, often accessed through ancient burial mounds known as sídhe. These powerful beings interact with humans, influencing fertility and legitimizing kings, offering a crucial glimpse into Ireland's legendary history and pre-Christian spiritual beliefs.