So what was going on in Malta that led to all this? Why did the first megalithic temple-builders in the world choose to make things so difficult for … - Graham Hancock

The Sabians were allowed to build a new Temple of the Moon God, and to continue their religious rites, after the Arab General Ibn Ghanam conquered Harran in the seventh century AD. This in itself is a sign of most unusual favor, since Islamic armies normally offered "pagans" the choice of either conversion or death. Even more interesting, however, is the Sabians' encounter with the Abbasid Caliph Abu Jafar Abdullah al-Ma'mun, who passed through their city in AD 830 and reportedly quizzed them intensively on their religion.
Remembering the Sabian pilgrimages to Giza, it is reasonable to wonder whether there is any connection with the fact that in AD 820, a decade before he visited Harran, it was Ma'mun who tunnelled into the Great Pyramid and opened its previously hidden passageways and chambers. Indeed, it is through "Ma'mun's Hole" that visitors still enter the monument today. Described by Gibbon as "a prince of rare learning," it seems Ma'mun's investigation was prompted by information he'd received about the Great Pyramid, specifically that it contained: 'a secret chamber with maps and tables of the celestial and terrestrial spheres. Although they were said to have been made in the remote past, they were suppposed to be of great accuracy.

The black mat formed on top of the layer of proxies,' Allen replies. 'Down here it has a lot of charcoal in it. But it also has algal remains so it's not just fire. The Younger Dryas changed the climate and made the area much wetter. Algae began to grow along the edges of the lakes.' He puts a hand on the black stripe along the arroyo wall: 'So the remains of about 1,000 years of dead algae, charcoal, and a lot of other stuff are all embedded in here, and at the bottom of it, where the impact happened, we find iridium, platinum, and a layer of melted spherules where the temperatures must have been so high that they would have melted a modern car into a pool of metal.

It is a curious mystery [...] that the exact same notions of the Seven Sages as the bringers of civilization in the remotest antiquity, and of the preservation and repromulgation of "writings on stones from before the flood," turn up in the supposedly completely distinct and unrelated culture of Ancient Egypt.
Of the greatest interest, at any rate, is the [Temple of Horus]'s idea of itself expressed in the acres of enigmatic inscriptions that cover its walls. These inscriptions, the so-called Edfu Building Texts, take us back to a very remote period called the "Early Primeval Age of the Gods" — and these gods, it transpired, were not originally Egyptian, but lived on a sacred island, the "Homeland of the Primeval Ones," in the midst of a great ocean. Then, at some unspecified time in the past, a terrible disaster — a true cataclysm of flood and fire [...] — overtook this island, where "the earliest mansions of the gods" had been founded, destroying it utterly, inundating all its holy places and killing most of its divine inhabitants. Some survived, however, and we are told that this remnant set sail in their ships (for the texts leave us in no doubt that these gods of the early primeval age were navigators) to "wander" the world.
[...] Of particular interest is a passage at Edfu in which we read of a circular, water-filled "channel" surrounding the original sacred domain that lay at the heart of the island of the Primeval Ones — a ring of water that was intended to fortify and protect that domain. In this there is, of course, a direct parallel to Atlantis, where the sacred domain on which stood the temple and palace of the god, whom Plato names as "Poseidon," was likewise surrounded by a ring of water, itself placed in the midst of further such concentric rings separated by rings of land, again with the purpose of fortification and protection.
Intriguingly, Plato also hints at the immediate cause of the earthquakes and floods that destroyed Atlantis. In the Timae