Annwn, appointed P9D-278 by the Tau'ri, is a planet in the Milky Way galaxy that has a Stargate and was part of the domain of the Goa'uld System Lord Manannan mac Lir before he gifted it to Arawn.
Overview[]
Annwn is a dim, mist-enshrouded world that revolves around a large M-class star, and although the planet is far enough from its star for its surface to be cool, the heavy cloud cover always has a hellish, furnace-like cast from the red-orange burning light that filters through. Annwn's continent Carmarthen is one of three continents on the planet and is covered in huge mountain ranges. These mountain ranges hide Arawn's secret laboratory complex, where he harbors his experiments using the Black Cauldron. Most of the animal life on Annwn is either tree-dwelling or airborne, with many of the tree-dwelling animals also being gliders, such as the biljagh, a large squirrel-like creature. The rich and dense atmosphere of Annwn allows trees to grow extremely tall, with all trees possessing a dense canopy that blocks out a great deal of sunlight, so many animals that have nocturnal cousins on other planets behave diurnally here. Outside of Carmarthen's mountain ranges, most of the terrain varies from hills to swamps, even at the equator. The only true deserts are in the polar regions, where it is too cold for precipitation to occur. (RPG: "Living Gods: Stargate System Lords")