Step 1: Towers. Make a 6x6 square using cobblestone. ...
Step 2: Walls. Make 3 more towers so that they form a square. ...
Step 3: Interior. Now, make the interior of your castle. ...
Step 4: Roof. On top of the pillars build the cobblestone roof. ...
Step 5: Rooms. Finally, make the rooms. ...
Step 6: Exterior.