Atlantis is a fictional location in the Marvel Comics Universe.
A few settlements survived the catastrophe. The priests and intellectuals of the city Netheria foresaw the Lemurian attack and fortified their city, and thus it sank intact. Netheria still exists today, ruled by Queen Kala.
Other ancient Atlanteans survived the sinking of the continent by various methods, including Dakimh the Enchanter, Varnae, and Stygyro.
About 8,000 years ago, a group of Homo mermanus nomads discovered the ruins of the city of Atlantis. They made the ruins of the human settlements in Atlantis their home and went on to develop a society there using as much of the material as they could scavenge from the wreckage. These people are thus often referred to as Atlanteans, as it is in the city of Atlantis that their first complex society emerged.
500 years after the settlement of Atlantis, another group of Homo mermanus left Atlantis to find their own city - this time in a part of the ruins of Lemuria, another continent submerged during the Great Cataclysm. These "Lemurians", as they now called themselves, discovered the Serpent Crown in the ruins of their city. The Serpent Crown has been crafted by ancient Atlantean alchemists, as a vessel empowered by the demonic Elder God Set. Through their leader Naga's exposure and extensive use of the ancient mystical device, they would become more serpent-like in appearance than their Atlantean cousins.
Atlanteans had little or no contact with their human cousins for millennia. However, the two races began to come into sustained contact, often hostile, beginning in the 20th century. On occasions, Atlanteans have invaded the surface world. Although the current Prince Namor the Sub-Mariner was initially hostile to the surface world (and has been at times since), eventually during the Second World War the kingdom of Atlantis also fought in alliance with the Allied Powers against the Axis Powers. Namor remains the reigning Prince of Atlantis to this day.
The city of Atlantis was recently destroyed as Namor evacuated the city, leaving behind the super-villain Nitro, who exploded, taking with him the city and Namor's traitorous son, Kamar.