The one on the right is the first (main) city gate of Birgu from the landward side – you can see it in yesterday’s picture. When you enter you will find yourself in small square and to your right you will find a bridge (I presume it was a drawbridge in it’s days) which is on one side of the square, hidden from the main gate.
Middle picture is a second gate. You go through it and find yourself in another small square. There isn’t a single window or door but when you turn your eyes, sideways you will see a third gate also hidden from sight as you enter gate one.
Third gate leads to the city.
The scope of the gates hidden from each other is to let in as many enemy troops as possible; they cannot retreat because their mates who are behind them are pushing to get in. From the top of the ramparts the defenders, who have been silently waiting, will shoot down or drop boiling tar on as many soldiers from the attacking troops as possible and when they see they cannot hold on and the enemy is about to burst the gate they retreat to the next defensive wall to assist the defenders already there. Same thing will happen and by the time the enemy gets through the city defences their strength as an army would be reduced possibly considerably and the battle will continue along the city streets.
Sorry for the long story and thank you for yourlooks, coments and fav's.
Ian
Love the middle gate!