Hellsgate (or Hellsgarth, in the original Dwarven language) is a vast mountain in the Moonstone Hills that anciently used to be a Dwarvish settlement homeycombing the whole mountain down to its depth, underground. Axion discovered that in the heart of Hellsgate there is a magic well that extends life and conquered the mountain, making it the heart of his empire. Later on, Axion was defeated and Hellsgate was left for centuries with no Master, until when Cawlis managed to gather an inhuman army around him and brought back Axion from the Blood stone to undeath, in order to learn his secrets. They will be both defeated by Yaztromo and Chadda Darkmane.
This place and its history are integral part of Shadowmaster novel