 Celtic otherworld, in Celtic mythology, the otherworld is the realm of the deities and possibly also of the dead. In Gaelic and Britonic mythology it is usually described as a supernatural realm of everlasting youth, beauty, health, abundance and joy. The otherworld is usually elusive, but various mythical heroes visit it either through chance or after being invited by one of its residents. They often reach it by entering ancient burial mounds or caves, or by going underwater or across the western sea. Sometimes, the otherworld is said to exist alongside our own located beyond the edge of the earth and intrudes into our world, signaled by phenomena such as magic mist. Certain changes in the weather, or the appearance of divine beings or unusual animals. An otherworldly woman may invite the hero into the otherworld by offering an apple or a silver apple branch, or a ball of thread to follow as it unwinds. The otherworld is usually called an Unwell Schmethology and Adelon in Arthurian legend. In Irish mythology it has several names, including Tirhidnog, Magnell and Emain Ablak. In Irish myth there is also Tecduan, where the souls of the dead gathered.