Meropis

Meropis is a location that appears in the Sonic the Hedgehog and its spin-off comic series' published by Archie Comics. In the Post-Super Genesis Wave timeline, it is an underwater city powered by magic rings, creating a watery shield that protects the citizens from harm.

Description
Much of Meropis is currently unknown, but it is a large city with a large watery-shield protecting it from intruders, namely Dark Gaia Monsters. What keeps the shield going are magic rings powered by the priestess' melody near the city, specifically at the Eusebes Shrine. The city as has City Guards, led by Captain Striker the Mantis Shrimp.

History
Razor the Shark and his Chao Crusher had went to the surface to bring three of the Knothole Freedom Fighters–Sonic the Hedgehog, Amy Rose, and Rotor the Walrus–to the Eusebes Shrine. However, the Freedom Fighters were interested at a nearby city to which Razor replies that the city is Meropis, but mentions that they are not heading there but instead outside the city. The next day, however, Cpt. Striker and the City Guard from Meropis came in the shrine land, only to find the Freedom Fighters "vandalizing" the land.

Trivia

 * Meropis is named after the ancient Greek island with the same name. How an underwater city draws any parallels with this fictional Greek island is beyond anyone's comprehension.