Before the continent of Atlantis sank about 20,000 years ago, its civilization had reached great technological heights. The priests and intellectuals of the city of Netheria in the southern part of the Atlantean continent foresaw that Atlantis would be attacked by the Deviant Empire based in Lemuria. Therefore, the people of Netheria enclosed their city in a dome of an unknown plastic-like substance and excavated and fortified their city's foundations. Consequently, when Atlantis sank, Netheria remained intact, and its people survived, having discovered a means of recycling their air supply. Netheria sank more deeply over the years until it finally came to rest in a huge sub-sea cavern. The Netherians renamed their realm the Netherworld, and are now known as Netherworlders.