diff --git a/Subsurface/Barotrauma.csproj b/Subsurface/Barotrauma.csproj
index b3a31c6df..220638680 100644
--- a/Subsurface/Barotrauma.csproj
+++ b/Subsurface/Barotrauma.csproj
@@ -811,6 +811,9 @@
     <Content Include="Content\Map\ruins2.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
+    <Content Include="Content\Map\ruins3.png">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
     <Content Include="Content\Map\shaft.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
diff --git a/Subsurface/Content/Map/RuinConfig.xml b/Subsurface/Content/Map/RuinConfig.xml
index 1b97eb801..f843d1829 100644
--- a/Subsurface/Content/Map/RuinConfig.xml
+++ b/Subsurface/Content/Map/RuinConfig.xml
@@ -6,7 +6,12 @@
   <structure prefab="RuinWallVertical" alignment="Left,Right" type="Wall"/>
   <structure prefab="RuinWallVerticalSmall" alignment="Left,Right" type="CorridorWall"/>
 
+  <structure prefab="RuinWallHeavyHorizontal" alignment="Top, Bottom" type="HeavyWall"/>
+  <structure prefab="RuinWallHeavyVertical" alignment="Left,Right" type="HeavyWall"/>
+  
+
   <structure prefab="RuinBack" alignment="Center" type="Back" commonness="3"/>
+  <structure prefab="RuinBackFractal" alignment="Center" type="Back" commonness="2"/>  
   <structure prefab="RuinBackCarvings" alignment="Center" type="Back" commonness="1"/>
 
   <item prefab="RuinBlock" alignment="Right,Top,Bottom,Left" type="Prop" commonness="5"/>
@@ -15,7 +20,6 @@
 
   <item prefab="RuinClaw" alignment="Bottom" type="Prop" commonness="5"/>
 
-
   <item prefab="Oxygenite Shard" alignment="Center,Right,Top,Bottom,Left" type="Prop" commonness="5"/>
   <item prefab="Sulphurite Shard" alignment="Center,Right,Top,Bottom,Left" type="Prop" commonness="5"/>
   
diff --git a/Subsurface/Content/Map/StructurePrefabs.xml b/Subsurface/Content/Map/StructurePrefabs.xml
index bf1c8422e..92442cdf6 100644
--- a/Subsurface/Content/Map/StructurePrefabs.xml
+++ b/Subsurface/Content/Map/StructurePrefabs.xml
@@ -200,6 +200,18 @@
     <sprite texture="Content/Map/ruins.png" sourcerect="896,192,128,832" depth ="0.061"/>
   </RuinWallVertical>
 
+
+  <RuinWallHeavyHorizontal category="Alien" castshadow="true"
+    width="128" height="128" resizehorizontal="true" body="true" health="100000">
+    <sprite texture="Content/Map/ruins3.png" sourcerect="352,896,672,128" depth ="0.06"/>
+  </RuinWallHeavyHorizontal>
+
+  <RuinWallHeavyVertical category="Alien" castshadow="true"
+    width="128" height="128" resizevertical="true" body="true" health="100000">
+    <sprite texture="Content/Map/ruins3.png" sourcerect="896,0,128,672" depth ="0.061"/>
+  </RuinWallHeavyVertical>
+  
+
   <RuinWallHorizontalSmall category="Alien" castshadow="true"
     width="128" height="54" resizehorizontal="true" body="true" health="500">
     <sprite texture="Content/Map/ruins.png" sourcerect="0,842,832,54" depth ="0.062"/>
@@ -221,6 +233,11 @@
     <sprite texture="Content/Map/ruins.png" sourcerect="512,0,233,512" depth ="0.981" />
   </RuinBackCarvings>
 
+  <RuinBackFractal category="Alien"
+    width="64" height="64" resizehorizontal="true" resizevertical="true">
+    <sprite texture="Content/Map/ruins3.png" sourcerect="0,0,640,896" depth ="0.98"/>
+  </RuinBackFractal>
+  
   <RuinBlock category="Alien" 
     width="514" height="296">
     <sprite texture="Content/Map/ruins.png" sourcerect="0,513,514,296" depth ="0.99" />
diff --git a/Subsurface/Content/Map/ruins3.png b/Subsurface/Content/Map/ruins3.png
new file mode 100644
index 000000000..b19e91419
Binary files /dev/null and b/Subsurface/Content/Map/ruins3.png differ
diff --git a/Subsurface/Source/Map/Levels/Ruins/RuinGenerator.cs b/Subsurface/Source/Map/Levels/Ruins/RuinGenerator.cs
index 64b3e1823..b905d2e88 100644
--- a/Subsurface/Source/Map/Levels/Ruins/RuinGenerator.cs
+++ b/Subsurface/Source/Map/Levels/Ruins/RuinGenerator.cs
@@ -301,17 +301,30 @@ namespace Barotrauma.RuinGeneration
         {
             List<RuinShape> shapes = new List<RuinShape>(rooms);
             shapes.AddRange(corridors);
-
-            //MapEntityPrefab hullPrefab = MapEntityPrefab.list.Find(m => m.Name == "Hull");
-
+            
             foreach (RuinShape leaf in shapes)
             {
+                RuinStructureType wallType = RuinStructureType.Wall;
+
+                if (!(leaf is BTRoom))
+                {
+                    wallType = RuinStructureType.CorridorWall;
+                }
+                //rooms further from the entrance are more likely to have hard-to-break walls
+                else if (Rand.Range(0.0f, leaf.DistanceFromEntrance, false) > 1.5f)
+                {
+                    wallType = RuinStructureType.HeavyWall;
+                }
+
+                //generate walls  --------------------------------------------------------------
                 foreach (Line wall in leaf.Walls)
                 {
-                    var structurePrefab = RuinStructure.GetRandom(leaf is BTRoom ? RuinStructureType.Wall : RuinStructureType.CorridorWall, leaf.GetLineAlignment(wall));
+                    var structurePrefab = RuinStructure.GetRandom(wallType, leaf.GetLineAlignment(wall));
                     if (structurePrefab == null) continue;
 
-                    float radius = (wall.A.X == wall.B.X) ? (structurePrefab.Prefab as StructurePrefab).Size.X * 0.5f : (structurePrefab.Prefab as StructurePrefab).Size.Y * 0.5f;
+                    float radius = (wall.A.X == wall.B.X) ? 
+                        (structurePrefab.Prefab as StructurePrefab).Size.X * 0.5f : 
+                        (structurePrefab.Prefab as StructurePrefab).Size.Y * 0.5f;
 
                     Rectangle rect = new Rectangle(
                         (int)(wall.A.X - radius), 
@@ -331,7 +344,7 @@ namespace Barotrauma.RuinGeneration
                     structure.SetCollisionCategory(Physics.CollisionLevel);
                 }
 
-
+                //generate backgrounds --------------------------------------------------------------
                 var background = RuinStructure.GetRandom(RuinStructureType.Back, Alignment.Center);
                 if (background == null) continue;
 
@@ -341,6 +354,7 @@ namespace Barotrauma.RuinGeneration
 
             }
 
+            //generate props --------------------------------------------------------------
             for (int i = 0; i < shapes.Count*2; i++ )
             {
                 Alignment[] alignments = new Alignment[] { Alignment.Top, Alignment.Bottom, Alignment.Right, Alignment.Left, Alignment.Center };
@@ -383,9 +397,11 @@ namespace Barotrauma.RuinGeneration
                 }
             }
 
+
+            //generate doors & sensors that close them -------------------------------------------------------------
+
             var sensorPrefab = ItemPrefab.list.Find(ip => ip.Name == "Alien Motion Sensor") as ItemPrefab;
-            var wirePrefab = ItemPrefab.list.Find(ip => ip.Name == "Wire") as ItemPrefab;
-           
+            var wirePrefab = ItemPrefab.list.Find(ip => ip.Name == "Wire") as ItemPrefab;           
 
             foreach (Corridor corridor in corridors)
             {
diff --git a/Subsurface/Source/Map/Levels/Ruins/RuinStructure.cs b/Subsurface/Source/Map/Levels/Ruins/RuinStructure.cs
index 24fd71ea0..cf16af530 100644
--- a/Subsurface/Source/Map/Levels/Ruins/RuinStructure.cs
+++ b/Subsurface/Source/Map/Levels/Ruins/RuinStructure.cs
@@ -10,7 +10,7 @@ namespace Barotrauma.RuinGeneration
     [Flags]
     enum RuinStructureType
     {
-        Wall = 1, CorridorWall = 2, Prop = 4, Back = 8, Door=16, Hatch=32
+        Wall = 1, CorridorWall = 2, Prop = 4, Back = 8, Door=16, Hatch=32, HeavyWall=64
     }
 
     class RuinStructure
@@ -88,7 +88,6 @@ namespace Barotrauma.RuinGeneration
 
             foreach (RuinStructure ruinStructure in matchingStructures)
             {
-
                 if (randomNumber <= ruinStructure.commonness)
                 {
                     return ruinStructure;