diff --git a/src/ch/zhaw/catan/Player.java b/src/ch/zhaw/catan/Player.java
index d7b7bc3..2011fe8 100644
--- a/src/ch/zhaw/catan/Player.java
+++ b/src/ch/zhaw/catan/Player.java
@@ -13,6 +13,7 @@ public class Player {
     private HashMap<Config.Resource,Integer> resources;
     private int roadsToUse;
     private int settlementsToUse;
+    private int citiesToUse;
 
     public Player (Config.Faction faction){
         //Datenfelder
@@ -91,9 +92,9 @@ public class Player {
 
     /**
      * This method has to be used when a player wants to build a settlement. It checks if a player has enough roads
-     * and resources to build one more. If player is able to build, the method substract the buildcost from the resources
-     * in possesion by the player.
-     * @return true if road can be created false if road can't be created
+     * and resources to build one more. If the player is able to build, this method subtracts the buildcost from the resources
+     * in possession by the player.
+     * @return true if road can be created false if road can't be created.
      */
     public boolean buildSettlement() {
         List<Config.Resource> costs = Config.Structure.SETTLEMENT.getCosts();
@@ -106,6 +107,23 @@ public class Player {
         return true;
     }
 
+    /**
+     * This method has to be used when a player wants to build a city. It checks if a player already has a settlement
+     * on that position and if he has enough resource to build one. If the player is able to build, this method subtracts
+     * the buildcost from the resources in possession by the player.
+     * @return true if road can be created false if road can't be created.
+     */
+    public boolean buildCity() {
+        List<Config.Resource> costs = Config.Structure.CITY.getCosts();
+        if ( citiesToUse == 0 || !checkRessourceToBuild(costs)){
+            return false;
+        }
+        for (Config.Resource resource : costs){
+            resources.put(resource,resources.get(resource)-1);
+        }
+        return true;
+    }
+
    //returns true if player has enough resources else false
     private boolean checkRessourceToBuild(List<Config.Resource> liste) {
         for (Config.Resource resource : liste) {
diff --git a/src/ch/zhaw/catan/SiedlerGame.java b/src/ch/zhaw/catan/SiedlerGame.java
index 9559984..5698f28 100644
--- a/src/ch/zhaw/catan/SiedlerGame.java
+++ b/src/ch/zhaw/catan/SiedlerGame.java
@@ -219,7 +219,7 @@ public class SiedlerGame {
         }
         //4. Insert Road to map
         board.setCorner(position, new Settlement(allPlayers.get(activePlayer).getFaction()));
-        //5. Give Resoure to bank
+        //5. Give Resources to bank
         bank.storeResourceToBank(Config.Structure.SETTLEMENT.getCosts());
         return true;
     }
@@ -239,6 +239,21 @@ public class SiedlerGame {
      */
     public boolean buildCity(Point position) {
         // TODO: OPTIONAL task - Implement
+        //1. Check if Corner.
+        if (!board.hasCorner(position)){
+            return false;
+        }
+        //2. Check if Settlement has already been built
+        Settlement atCurrentPosition = (Settlement) board.getCorner(position);
+
+        //3. Can player build a City.
+        if(!allPlayers.get(activePlayer).buildCity()){
+            return false;
+        }
+        //4.Insert City into the map.
+        board.setCorner(position,new City(allPlayers.get(activePlayer).getFaction()));
+        //5. Give resources to the bank.
+        bank.storeResourceToBank(Config.Structure.CITY.getCosts());
         return false;
     }