As I noted earlier the term ἐκκλησία originally meant an assembly of people not a physical building. As such when Clement writes in to Theodore that Mark:
left his composition to the church in Alexandria (τῇ ἐκκλησίᾳ τῇ ἐν Ἀλεξανδρείᾳ), where it even yet is most carefully guarded, being read only to those who are being initiated into the great mysteries.
The closest we ever get to the particular phrase 'the church in Alexandria' in the early Patristic writings are two references in Athanasius's Contra Arianos to "the Holy Church of God abiding at Alexandria" (τῇ ἁγίᾳ ἐκκλησίᾳ τοῦ θεοῦ τῇ ἐν Ἀλεξανδρείᾳ 37, 84). Given that there were many buildings in Alexandria at the time of Athanasius, we should surmise that Clement was not referring to a building at all but the gathering of Christians which happened to take place in a single location at this time - i.e. at the site of what is now called the 'martyrium of St. Mark' in the Boucalia in the eastern shores of Alexandria just beyond the city walls.
This gathering clearly took place in a tent structure as we see from Clement's statement in Stromata Book Five:
Now concealment is evinced in the reference of the seven circuits around the tabernacle, which are made mention of among the Hebrews; and the equipment on the robe, indicating by the various symbols, which had reference to visible objects, the agreement which from heaven reaches down to earth. And the covering and the veil were variegated with blue, and purple, and scarlet, and linen. And so it was suggested that the nature of the elements contained the revelation of God. For purple is from water, linen from the earth; blue, being dark, is like the air, as scarlet is like fire.
As I have noted before the description of the place the ἐκκλησίᾳ gathered in to Theodore so closely resembles the description of the tabernacle of the ancient Israelites that I accept the idea that the Alexandrians did not actually come together in a physical building per se. The symbolism of an Egyptian ἐκκλησίᾳ gathering in a replica tabernacle is obvious no less than their apparent interest in another baptism called 'the redemption.' The idea was clearly that the experience of the ancient Israelites was 'typical' of what was to come to fulfillment at the time of the messiah - i.e. a heavenly ascent.
Most reconstructions of the Israelite tabernacle are so bad it is utterly embarrassing. I actually have vivid memories of my visit to the exhibit at the Holy Land Experience (an amusement park in Orlando). What the goyim always get wrong is that they concentrate their attemption on the inner sanctum too much. They ignore the explicit evidence that the whole structure - i.e. not just the furniture and objects at the heart of the tabernacle - was understood to represent the cosmos.
To this end we can be absolutely certain that Clement and his Alexandrian community gathered in a tent structure that had an inner adyton surrounded by seven outer circuits. The so-called 'Ophite diagram' was clearly related to the physicality of both the contemporary Alexandrian and ancient Israelite tabernacle. There should also be no doubt that the ancient Israelite structure was further divided into twelve 'zones' related to the twelve tribes. To this end when you start looking at the developing image that comes before us, both modern and ancient ἐκκλησίᾳ in Egypt took on the shape of a zodiac.
It is well established of course that the twelve tribes are related to the twelve signs of the zodiac. Just take a second look at the four living creatures that surround the heavenly throne in the vision of Isaiah, Ezekiel or the Book of Revelation. The animals clearly represent the four cardinal points in the astrological circle:
The point of course is that there is no good reason to understand that the Alexandrian followers of Mark took a deep interest in the numerological significance of the number 360 for the very same reason - i.e. the year itself was divided into twelve months of thirty days (cf. Irenaeus AH 2.24 etc.).
What I want to explain to my readers again is that when we speak of 'the mysteries of the Alexandrian Church' it is impossible not to see that they developed around the physical structure that the ἐκκλησίᾳ originally gathered in - viz. a massive replica of the cosmos - and where the purpose of initiation was to liberate oneself from being stuck in the 'outer perimeter' i.e. pass through the seven circuits to the inner sanctum.
The same symbolism is still depicted on the throne of St. Mark which was ultimately taken to Venice in the ninth century CE.
