The Bible indicates that there are 3 heavens. An informative article in the link below. This explains a lot! The heavenly Zion is strongly connected to Mount Zion and Mount Zaphon. Please forgive any mistakes I may make in trying to understand what is what. I am very open to correction and welcome any feedback. In Isaiah 14:13 we are told (re Satan) "You said in your heart I will ascend to the heavens above the stars of God. I will sit enthroned on the Mount of Assembly (I take this to be the heavenly Temple) on the utmost heights of Mount Zaphon. Psalm 48:2 says - "Beautiful in it's loftiness, the joy of the whole earth, like the heights of Zaphon is Mount Zion, the city of the Great King."
Satan wants to ascend to the heights (above Mount Zaphon) and claim the throne in God's heavenly Temple above Mount Zaphon. Above the earthly Mount Zion there is surely a corresponding heavenly body? Attempting to unscrabble all the questions in my brain, I tentatively surmise that the end-time chaos taking place in the heavens, occurs on different levels of the heavens. We know that the highest heaven contains the Throne of God. That much is a given. Which makes Satan's rebellion and apostasy occurring in "the holy place - let the reader understand" much clearer. This also - in some ways - answers the question of the man-child in Revelation 12 being swept up to God's Throne before the dragon can devour him. These things are happening in the heavens, plural. They are not taking place on earth or in an earthly temple.
Revelation 11:19 has the door of heaven opening. Which means that we, on earth, can see into heaven. For example, in Matthew 3:16-17 we are told "As soon as Jesus was baptised, he went up out of the water. At that moment heaven was opened and was seen the spirit of God descending like a dove and alighting on him. And a voice from heaven said, "This is my son, whom I love; with him I am well pleased". Another example of heaven opening to earthly eyes takes place in Acts 7:55-56 - "But Stephen, full of the Holy Spirit, looked up to heaven and saw the glory of God and Jesus standing at the right hand of God. 'Look, he said, I see heaven open and the Son of Man standing at the right hand of God'.
I remain convinced that The Apostasy takes place in the heavenly realms and that we earth dwellers will see it - because the door to heaven opens and allows us to see into that realm. Wowza - we are going to see some incredible things in the very near future. Hallelujah. This is exactly why we are urged to lift up our heads (to observe the drama going on in heaven) because this means our redemptions draws near. We will all be standing, watching and waiting for our blessed hope. Such a stunning realisation.
Please come, LORD Jesus.