Building around the keep: the main gate

Once the main blocks of the keep are there, tower and great hall, it is about time to build around them. Basically what is needed is a curtain wall around the keep to protect it from external attacks and one or several gates to access to it. Since there is not possible to transport water in the current Minecraft PE version and the proximity to the sea, a moat around the castle is neither possible nor a priority. So, where to start? The hill on what the castle is being built descends to a bay where a harbor could be built one day, so it looks like a good idea have to place the castle main gate in that direction. That will also allow for a long walk around the great hall entrance where invaders will be trapped in the corridor between curtain wall and keep where the defenders could attack from above. For the time being the main gate will be two main towers with a bridge connecting them. Battlements and arrow slots allow defend the main gate from that bridge. The towers have stone walls and two floors wooden beam floors. Not having a final decision on the gate doors, I will build them later.