Mt. Joffa is a large mountain located towards the north of Atylo. This mountain encases a large temple known as the Signia Temple. The temple holds evidence that this was the last remaining location where the X-nelians occupied before their disappearance during the X-nelian War. The mountain is currently being excavated by Dorn's Army where their objective is unclear. Mt. Joffa was first featured in Lego Metroid Episode 5 - Darkness, where deep underground Dal-G is seen speaking to a large entity referring to it as Mother.