Vesuvio

Vesuvio is a secret and ancient underground city, located on an island outside the southeastern coast of Soumerca. It is a gigantic cavernous habitat underneath Mobius' largest volcano. It is the residence to the dragons of Mobius and was the home of Dulcy.

History
According to myth, eons ago Vesuvio was the home to the ancestors of the present day Mobian Dragons. Legend has it that the Ancient Walkers forged the Magic Golden Rings on the banks of Vesuviou's lava lake. Under unknown circumstances, however, the dragon ancestors living in Vesuvio left the city, leaving it abandoned.

During the First Robotnik War, when the dragons of Mobius came under attack by Dr. Robotnik's forces, the few colonies of remaining dragons retreated to Vesuvio, where they could live in safety. Joined by more surviving colonies, the dragons re-colonized Vesuvio and established a community there with Glint in charge.

When Dulcy returned to Vesuvio after her exile, Vesuvio was discovered by Dr. Eggman after a group of roboticized dragons followed her there. Intending to conquer Vesuvio and roboticize the remaining dragons, Eggman had the roboticized dragons attack the ancient city. Dulcy, however, managed to fight alongside the other free dragons residing in Vesuvio, and together they destroyed the roboticized dragons. Afterwards, due to her bravery and performance in battle, Dulcy was granted full pardon and had her citizenship in Vesuvio renewed, and became as well the official ambassador between the dragons in Vesivio and the outside world.

Trivia

 * Vesuvio is presumably named after the real-life mountain volcano Vesuvius in Italy.