The Citadel is home to the First Tribe. They are Bosmer descendants who have been living on the island since time immemorial and probably at some occasion in history, came over from Valenwood. Once, their Citadel in the east of the island was the central hub of a great empire, but now, they’re just a shadow of their former glory. Detached from the rest of the Bosmer culture, they’ve developed their own, and The First Tribe is still inhabiting the darkened halls of The Citadel.
You can’t make a tropical island without at least attempting to recreate a Mayan or Aztec ruin, now can you? The Dwemer/Markarth pieces are great for that. Oh, and yes, by the way, I’m a big fan of the Tropico series, if you haven’t already noticed.