Appologies ! I thought that is what it was. I thought the stonework in the top left was a ruined building rather than a cave. I guess as soon as you colour it then it would have instantly made it clear. You just carry on with your map as you intended it. Maybe this one will be level 1 and the current dungeon will be level two. This one looks closer to the surface since it has the rail cart. I will plan a map with the rail tracks going up to some entrances then.