Mystics have described the Arch as being composed of uncountable diamond facets that shimmer with a brilliance indescribable in mortal words. The Arch is said to be the spine of the creator god Anu, and to hum with a remnant of its essence that permeates all of Heaven. Many in Sanctuary, from the mystics of Aranoch to the priests of Skovos, agree that an echo of Heaven can be found at the height of meditation. Deckard Cain speculated that this echo might be the harmony that comes from the arch itself.