Lemuria

Lemuria was once an advanced seafaring civilization. Although some of the members' whereabouts are unknown, they have left countless artifacts under the Earth's oceans.

Location
It is found that in the episode More Thunder and Lightning of Season 3, Lemuria is behind the gates from Season 2's, The Gates.

Members
Alpheus Benthos

Ant Nekton

Queen Doreus

Fontaine Nekton

Kaiko Nekton (by marriage)

The Lemurians

Many people in the world (descendants)

Nereus

Other heirs and royal family members

The Scientists (Later the Guardians)

William Nekton

Many people who survived the sinking joined other cultures and societies, and over time, their descendants forgot about Lemuria and its legacy was lost to time.

Government And Monarchy
Not much is known about Lemuria's government, however, it is known that the government type was a monarchy. It is unknown what type of monarchy, as it was only stated in the episodes that Queen Doreus was its last ruler. It may have been a kingdom, queendom, or where the most worthy or oldest heir takes the throne.

Additionally, Ant may have made a mistake in the episode The Scepter, after he says to William that Nereus would be the king and Doreus' scepter would belong to him. William replies by saying that Ant is the chosen one and that the scepter is his. This would suggest that the youngest heir who is connected to the scepter and the ephemychron takes the throne. Of course, it may have been a mistake. If it was, then that would mean that William and Kaiko are the current rulers of the city.

Trivia

 * It is unknown if Lemuria was a kingdom or queendom, as it is only stated that Queen Dores was the last ruler. However, Lemuria could have a system in which the oldest or most worthy heir takes the throne
 * There were two lines of the royal family, meaning that Queen Dores may have had cousins, meaning that she had an aunt or an uncle who didn't like her when she became the Queen, so they rebelled against her trying to take the throne
 * Some of the Guardians are descended from the Lemurians, as Dores trusted the Scientists with the knowledge of Lemuria before it sunk
 * There is a type of algae floating around the city which is able to make any inanimate object, as well as all living things, turn into stone, thus the reason why the city is preserved so well
 * Queen Dores' sarcophagus was made eons ago and is located here but without her body
 * Lemuria sunk due to the Kraken in front of the city's gates
 * Lemuria may be based on the continent of Lemuria zoologist Philip Schlater put forward in a now debunked scientific theory to explain the existence of the presence of Lemur fossils in disconnected areas of the world.