I explored it in 2004 when it was semi abandoned and laying derelict (you could walk through the front gate). Since then it has been refurbished and opened up as a museum, they actually fire those 6 inch guns on the first Sunday of every month. All the buildings and doors to tunnels are alarmed, it has a loud clanging bell that can be heard across the local area and there are house all around it.
Blakjak of the Sydney branch of the Cave Clan.