If you remember the Warehouse in the market district there is a hidden part of it behind some kind of cabinet. How the hell do i get inside?
i need to get in there for a gift item
When you invade Arl Howe's estate in Denerim, you'll run into a Grey Warden named Riordan. Free him (I don't think this is optional) and then talk to him later when you return to Arl Eamon's estate in the market district. He should have some information about it for you then.
PS, this is after you finish assembling your army and start the Landsmeet portion of the game.