The Inner Sanctum is the "inner" part of the Temple of the Fates. It lies beyond the Throne of Lahkesis, and Kratos enters it by shattering the throne room's central mirror (with Lahkesis and Atropos trapped inside it). From there, Kratos eventually comes to a very long winding path that runs along the outside of Clotho's Loom Chamber. Kratos must descend down the path, defeating hordes of foes all the way, which include Cursed Legionnaires, Fates Juggernauts, Fates Sentries, Sirens, Gorgons, Hades Minotaurs, Satyrs and Cyclopes. At the end, he'll come to the gates to the Loom Chamber.
It should be noted that before entering Clotho's chambers, Kratos sees three murals describing past, present, and future events. The first referencing the Great War between the Titans and Olympians in the past and the threat of its revival, the second showing a lone man (likely Kratos himself) surveying the carnage of a great battle that is waging on below him, and the last alluding to the journey of the three Wise Men toward the birth of Christ. It is possible that the last mural referencing Jesus Christ's birth and the rise of Christianity is there as a way of conveying the real life turn from polytheism, the worship of multiple Gods, such as those in Greek Mythology, to the worship of one God and creator, namely Monotheism. Beyond the key players in the Greek Mythological world being dead the rise of Monotheism such as Christianity (which is notably the world's dominant religion) only further drove figures such as Zeus into things of legend and myths. There has also been some debate as if this Monotheistic reference is a clear cut statement from the developers that in their perception of Greek Mythology the God whom Jews, Christians, and Muslims worship can exist right alongside figures such as Zeus and not be contradicted as being exactly what their religions claim about Him.