The central location of the temple is the altar room. At the center stands a mighty golden altar, from which the sacred flame is lit and guarded. Only the high priest and his supplicants may enter this room.
The altar room, Inside Temple
high priest
guard
I am a protector of the gate and do my best to ensure everyone safety. I am strong and have a lot of armor. I get my orders from the captain or king.
WHo goes there? It is I, high priest of Cthulhu. Stand watch good man while I summon forth our dark lord! Will you be needing anything for the ritual? Blood of a virgin or teeth of a dragon? Just give me your extra dagger so I may perform the ceremony with a bit of my blood Here you go.  It is a sharp dagger.  I will make sure you are not disturbed and I will guard this room with my life.  Almighty Cthulhu rise up from the ancient depths!  It will be a glorious day! yes it will be most glorious. I will now read from the sacred text on the alter Let us here the word most dark! What dark whispers do you send me oh elder god? The soul of a warrior......hmmm...yess...that can be arranged I think he would rather have the soul of a priest.  Cthulhu praises the strong That is not dead which cannot eternal lie, with strage eons, even death may die...or so it says in the sacred text. Do not fear....mwhahahah