@Atlantis, officially the Kingdom of Atlantis, is an underwater kingdom located somewhere deep in the @Atlantic Ocean. It is home to the ancient, isolated, and highly advanced @Atlantean culture.

History

Mythic Legends

The human myth is that a Greek philosopher named Plato had been told the story of the island of Atlantis by his father, Solon, who had been told the story by an Egyptian priest who was carving it into a column for a temple. The island was in the era 9600 BC. However, after its people tried to invade Athens, in a single night and day of misfortune the island of Atlantis sank into the depths of the ocean. Dozens of possible locations for the city have been suggested, including Santorini, Greece, Azores in the Atlantic, and off the coast of Cornwall in New England.

Quest for the Golden Fleece

@Percy Jackson had a dream of him following @Tyson into the court of Poseidon. He saw his father in a magnificent hall with cobbled floor of pearls and @Poseidon sitting on a throne of coral. He told Percy to 'Brace yourself' just like he said in the letter delivered by @Hermes. Tyson got an internship working in the @Underwater Forges to make weapons for the Olympians for the Second Titan War.

Quest to Rescue Artemis

Percy sent Tyson an Iris Message in Atlantis, where Tyson talked about his new job and how some of the older sea spirits were making trouble for Poseidon in Atlantis, waging war against him.

Politics

The government of Atlantis is considered to be a monarchy as it is ruled over by @Poseidon, his family, as well as a cabinet known as the Royal Council, whose role is to typically advise and assist the day-to-day operation of the Atlantean government.

Crown of Thorns

The Crown of Thorns is an @Atlantean defensive network. An ancient relic from a long bygone era in @Atlantis, the artifact known as the Crown of Thorns is a vast protective network of deep mystical nature entwined with greater Atlantean science which has served as the ultimate defense from outside invasion.

The magic of such an apparatus is such that it can resist the force of crushing tidal waves and even an assault by some of the most powerful individuals the world has ever seen, the influx of magic from the Crown also has the effect of accelerating Atlantean adaptation to undersea life. The only way to enter and exit the city is through magical medallions for easy recognition by the barrier, but its effects aren't without fault.