This came into my mind when reading the article about the main city hall. What is below San Cielo?

Silverhelm could do a repeatable mission which takes place under the main city of the game. Dark, cold and creepy ruins in the deep. Even deeper than the sewers. Some high level or endgame content could take place there for heroes and villains (or even both together teaming up against a much bigger thread?)

I would do this very late in the lifetime of the game becuase I think the map of VO should grow in expanse first and later in depth and altitude.

But the main idea was to have a creepy dungeon right below the shining city of San Cielo where the past overtakes the players...