How do you get to the closed off area in the southeast of the Dwarf Fortress? I can see a spot south of the undead warrior where there is just a single square of wall in my way and I've searched for hidden buttons, but I haven't been able to find any. I cheated my way in, and there is a set of magical gold-colored armor there.

I believe this topic covers the same question, though it has no answer :(
http://www.gog.com/forum/stonekeep/secret_area_in_dwarven_halls_not_the_locked_room

Can someone upload a savegame from that location?

I second this.