Dungeon World: World of Dungeons!
I asked the Internet…
And came up with two reasons the world is full of dungeons:
1. The Dwarves built vaults to survive Ragnarok, and you have only recently emerged
2. The Ancients hid powerful artifacts away to keep them safe from mortal hands, but those Ancients seem to be long-gone
Otherwise, we’ll start from the setting implied by the Dungeon World book and go from there. A lot of questions about the setting will be answered by us, in play, as we play to find out what happens.