Caerphilly Castle Main Entrance

First, just to get to the main entrance, you have to pass through 2 different guard houses and cross two separate moats (with draw bridges). The main guardhouse has a sally-port setup whereby there are 2-3 different doors. They raise one, let you in and close it behind you. There, you are interrogated with guards watching through small arrow slits in the walls and through holes in the ceiling. If allowed, you then pass through the other two gates in similar fashion. This place must have been extremely secure.