diff --git a/dat/hellfill.lua b/dat/hellfill.lua
index d7675e19b..00175ffd3 100644
--- a/dat/hellfill.lua
+++ b/dat/hellfill.lua
@@ -410,6 +410,20 @@ hells = {
       end
       des.terrain(outside_walls, " ");  -- return the outside back to solid wall
    end,
+
+   -- 7: open cavern, "mines" with more space
+   function ()
+      des.level_init({ style = "solidfill", fg = " ", lit = 0 });
+      des.level_flags("mazelevel", "noflip");
+      des.level_init({ style="mines", fg=".", smoothed=true ,joined=true, lit=0 });
+      local sel = selection.match("."):grow();
+      des.terrain({ selection = sel, typ = "." });
+
+      local border = selection.rect(0,0, 78, 20);
+      des.terrain({ selection = border, typ = " " });
+      des.wallify();
+   end,
+
 };
 
 local hellno = math.random(1, #hells);