It seems there is much mystery and intrigue centred around ancient civilizations. Some of which is due to drawings of “spaceships” and other “godly” beings. The other relies on the lack of current technology to explain methods of construction used thousands of years ago.
It is certainly possible that a more advanced being had travelled to parts of Earth thousands of years ago to provide highly advanced technology to the ancient civilizations. It is also probable, though slightly less likely, that these beings were just humans travelling back in time after the fall of many societies which removed the history of the pyramids from their history books and making the past so much more interesting to travel to/share technology with.
As for the construction methods used to create massive statues and other elaborate structures, there are some plausible answers that seem to be inconceivable to most “scientists” due to being far too mystical. I propose that societies of the past had heightened telekinetic abilities which allowed them to carve, mould and move massive structures. I also posit that they possessed a primitive technology that we have yet to rediscover as it has become lost in time due to it being so simple that we have not thought to look for remnants of such a construction. Yet this basic technology was highly useful for such needs as moving massive blocks.
Sure these ideas are a bit far-fetched but only so much as the idea that an alien race came to Earth and helped primitive societies build, seemingly, meaningless structures that could hardly benefit such an advanced species to begin with.
Scientists are also mystified by the complexity of which space is represented by the ancient cultures. Its not so hard to fathom once you consider that all they may have had was a very strong mathematical/spacial understanding that we lack today due to modern technology. We have actually become far less in-tune with the universe as telescopes and other imaging devices do all the work for us, while for them all they had was the night sky to entertain themselves which was pondered upon for a great deal of time by a great many scientists of their time.
There may be even other, more simple, possibilities that others have considered but have yet to make mainstream knowledge. We are simple, narrow minded creatures and for that we will be defeated.