diff --git a/castle.js b/castle.js
new file mode 100644
index 0000000..9b3c03e
--- /dev/null
+++ b/castle.js
@@ -0,0 +1,52 @@
+load($SCRIPT_DIR + "/fort.js");
+//
+// a castle is just a big wide fort with 4 smaller forts at each corner
+//
+function castle (side, height, drone)
+{
+	 // 
+	 // use sensible default parameter values
+	 // if no parameters are supplied
+	 //
+	 if (typeof drone == "undefined")
+		  drone = new Drone();
+	 if (typeof side == "undefined")
+		  side = 24;
+	 if (typeof height == "undefined")
+		  height = 10;
+	 if (height < 8 || side < 20)
+		  throw new java.lang.RuntimeException("Castles must be at least 20 wide X 8 tall");
+	 //
+	 // remember where the drone is so it can return 'home'
+	 //
+	 drone.chkpt('castle');
+	 // 
+	 // how big the towers at each corner will be...
+	 //
+	 var towerSide = 10;
+	 var towerHeight = height+4;
+
+	 //
+	 // the main castle building will be front and right of the first tower
+	 //
+	 drone.fwd(towerSide/2).right(towerSide/2);
+	 //
+	 // the castle is really just a big fort with 4 smaller 'tower' forts at each corner
+	 //
+	 drone = fort(side,height,drone);
+	 //
+	 // move back to start position
+	 //
+	 drone.move('castle');
+	 //
+	 // now place 4 towers at each corner (each tower is another fort)
+	 //
+	 for (var corner = 0; corner < 4; corner++)
+	 {
+		  // construct a 'tower' fort
+		  fort(towerSide,towerHeight,drone); 
+		  // move forward the length of the castle then turn right
+		  drone.fwd(side+towerSide-1).turn(); 
+	 }
+	 return drone.move('castle');
+}
diff --git a/castles-interlocking.png b/castles-interlocking.png
new file mode 100644
index 0000000..e190626
Binary files /dev/null and b/castles-interlocking.png differ