The Sunken Caldera is a dormant volcano buried deep within the sea. Only the edges of the once great mountain peak crest above the waves, forming it into a sort of bowl surrounding the city within, and beneath, the Glass Dome.
The Glass Dome - 22 Edit
The Glass Dome is an isolated area with only a few entrance. In the waters of this dormant, sunken volcano, is a large arena located in a glass dome, lit by alternating lights, that change between the colours of the rainbow made to cut through the naturally dim light. This arena is designed, and meant for those that focus on Pokemon Contests,, making the arena itself rather aesthetically pleasing. The glass bubble is environmentally controlled, allowing it to change the environment to suit various themes and climates.
NAME - 23 Edit
Otherwise known as The City of Harmony, is an advanced artificial island built above the Glass Dome, where a water based battling arena sits in the middle. The arena is big enough for even the larger water pokemon to comfortably battle in it, looking more like a man-made lake than anything else. Personal sailboats are available for rent within the walls of the Caldera, providing a fun activity for tourists. A platform can be raised in the arena to offer large neutral grounds, to host the World Tournament that takes place on the Island once a year, which many from around the world come to fight it out for the illustrious title of Sileda Island Champion.