The ruins of Archéopolis, the last remnant of Atlantis.

Atlantis was a kingdom the size of a continent, which existed on Earth 12000 years before the adventures of Thorgal took place. A great catastrophe caused the kingdom to disappear into the ocean, and only the city of Archéopolis, located on the edge of Atlantis, remained.

Unfortunately these last ruins of Atlantis were also destroyed when Sargon's spaceship crashed into the above desert following a failed launch. The desert collapsed on top of the remnants.[1]

Before the great catastrophe, Atlantis was inhabited by the Star People.