Question about Dungeons

[DiasFlac]

There are rare dungeon drops and item sets. They have a green background when you view them in your inventory. You can start collecting a set when you run Satasha, Tam Terra Depot (or whatever it is called), and Copperbell mines. I've not seen anything in the field drop a rare item, though.

Thank you both for your replies. One more question while we're on the subject. How are other dungeons unlocked?