diff --git a/src/engine/InterestManagement/Terrain.java b/src/engine/InterestManagement/Terrain.java
index c404286d..f49eb9f3 100644
--- a/src/engine/InterestManagement/Terrain.java
+++ b/src/engine/InterestManagement/Terrain.java
@@ -35,15 +35,15 @@ public class Terrain {
         this.zone = zone;
         this.heightmap = this.zone.terrain_image;
 
-        // Configure PLANAR zones to use the same
-        // 16x16 pixel image that all other flat
-        // terrains share.
+        // Configure PLANAR zones to use the same 16x16 pixel image
+        // that all similar terrains share.  (See JSON)  Guild zones
+        // use an inverted clone of this heightmap.
 
         if (this.zone.terrain_type.equals("PLANAR"))
             if (this.zone.guild_zone)
-                this.heightmap = 1006301;
+                this.heightmap = 1006301;  // all 255
             else
-                this.heightmap = 1006300;
+                this.heightmap = 1006300;  // all 0
 
         // Load pixel data for this terrain from cache
 
@@ -110,7 +110,7 @@ public class Terrain {
         // Interpolate height for this position in terrain
 
         float interpolatedChildHeight = terrainZone.terrain.getInterpolatedTerrainHeight(terrainLoc);
-        interpolatedChildHeight += terrainZone.worldAltitude;
+        interpolatedChildHeight += terrainZone.global_height;
 
         return interpolatedChildHeight;
     }
diff --git a/src/engine/devcmd/cmds/GetHeightCmd.java b/src/engine/devcmd/cmds/GetHeightCmd.java
index bb9b56f9..9b8266e7 100644
--- a/src/engine/devcmd/cmds/GetHeightCmd.java
+++ b/src/engine/devcmd/cmds/GetHeightCmd.java
@@ -44,7 +44,7 @@ public class GetHeightCmd extends AbstractDevCmd {
 
         this.throwbackInfo(playerCharacter, "Current Zone : " + currentZone.zoneName);
         this.throwbackInfo(playerCharacter, "Heightmap Zone : " + heightmapZone.zoneName);
-        this.throwbackInfo(playerCharacter, "Global Height: " + heightmapZone.worldAltitude);
+        this.throwbackInfo(playerCharacter, "Global Height: " + heightmapZone.global_height);
         this.throwbackInfo(playerCharacter, "Sea Level: " + heightmapZone.seaLevel);
         this.throwbackInfo(playerCharacter, "Grid : " + Math.floor(gridSquare.x) + "x" + Math.floor(gridSquare.y));
         this.throwbackInfo(playerCharacter, "Blend: " + heightmapZone.terrain.terrainBlend(zoneOffset));
diff --git a/src/engine/devcmd/cmds/SeaAuditCmd.java b/src/engine/devcmd/cmds/SeaAuditCmd.java
index f5cdbdde..ec0e6c96 100644
--- a/src/engine/devcmd/cmds/SeaAuditCmd.java
+++ b/src/engine/devcmd/cmds/SeaAuditCmd.java
@@ -26,7 +26,7 @@ public class SeaAuditCmd extends AbstractDevCmd {
                           AbstractGameObject target) {
 
         for (Zone zone : ZoneManager.getAllZones())
-            if (zone.seaLevel > zone.worldAltitude)
+            if (zone.seaLevel > zone.global_height)
                 this.throwbackInfo(playerCharacter, zone.getObjectUUID() + zone.zoneName);
     }
 
diff --git a/src/engine/devcmd/cmds/ZoneInfoCmd.java b/src/engine/devcmd/cmds/ZoneInfoCmd.java
index 3786d1b4..53e7ac61 100644
--- a/src/engine/devcmd/cmds/ZoneInfoCmd.java
+++ b/src/engine/devcmd/cmds/ZoneInfoCmd.java
@@ -101,7 +101,7 @@ public class ZoneInfoCmd extends AbstractDevCmd {
         output += newline;
         output += "Sea Level = " + zone.seaLevel;
         output += newline;
-        output += "World Altitude = " + zone.worldAltitude;
+        output += "World Altitude = " + zone.global_height;
         throwbackInfo(player, output);
 
         City city = ZoneManager.getCityAtLocation(player.getLoc());
diff --git a/src/engine/gameManager/ZoneManager.java b/src/engine/gameManager/ZoneManager.java
index ae544cfe..90fbb599 100644
--- a/src/engine/gameManager/ZoneManager.java
+++ b/src/engine/gameManager/ZoneManager.java
@@ -453,7 +453,7 @@ public enum ZoneManager {
         }
     }
 
-    public static float caclulateWorldAltitude(Zone zone) {
+    public static float calculateGlobalZoneHeight(Zone zone) {
 
         float worldAlttitude = MBServerStatics.SEA_FLOOR_ALTITUDE;
 
diff --git a/src/engine/net/client/handlers/PlaceAssetMsgHandler.java b/src/engine/net/client/handlers/PlaceAssetMsgHandler.java
index 6ef021a3..c62c7e8c 100644
--- a/src/engine/net/client/handlers/PlaceAssetMsgHandler.java
+++ b/src/engine/net/client/handlers/PlaceAssetMsgHandler.java
@@ -792,7 +792,7 @@ public class PlaceAssetMsgHandler extends AbstractClientMsgHandler {
         ZoneManager.addPlayerCityZone(zoneObject);
         serverZone.addNode(zoneObject);
 
-        zoneObject.worldAltitude = ZoneManager.caclulateWorldAltitude(zoneObject);
+        zoneObject.global_height = ZoneManager.calculateGlobalZoneHeight(zoneObject);
 
         cityObject.setParent(zoneObject);
         cityObject.setObjectTypeMask(MBServerStatics.MASK_CITY); // *** Refactor : should have it already
diff --git a/src/engine/objects/Zone.java b/src/engine/objects/Zone.java
index 1878e903..8376a151 100644
--- a/src/engine/objects/Zone.java
+++ b/src/engine/objects/Zone.java
@@ -56,7 +56,7 @@ public class Zone extends AbstractGameObject {
     public boolean isNPCCity = false;
     public boolean guild_zone;
     public String hash;
-    public float worldAltitude = 0;
+    public float global_height = 0;
     public float seaLevel = 0f;
     public float sea_level_offset = 0;
     public static final Set<Mob> respawnQue = Collections.newSetFromMap(new ConcurrentHashMap<>());
@@ -230,7 +230,7 @@ public class Zone extends AbstractGameObject {
         }
 
         this.setBounds();
-        this.worldAltitude = ZoneManager.caclulateWorldAltitude(this);
+        this.global_height = ZoneManager.calculateGlobalZoneHeight(this);
         setSeaLevel();
     }
 
@@ -251,7 +251,7 @@ public class Zone extends AbstractGameObject {
                 this.sea_level = this.parent.sea_level + this.sea_level_offset;
                 break;
             case "SELF":
-                this.sea_level = this.worldAltitude + this.sea_level_offset;
+                this.sea_level = this.global_height + this.sea_level_offset;
                 break;
         }
     }