Arcadia is in SMP 1, and the locked chests belong to me, if that makes finding them any easier. I really hope there's no one nearby, since it was a ludicrous hike to get there.
Sorry rbloodgoog, 2 settlements nearby and very large at that. It's a good idea to scan the area within 3000 blocks on the livemap. I recommend you move 1000 east. PM me if you need help with this.
