Pharos in the Nile Delta has been suggested by R. McQuillen as the location of Atlantis. It should be noted that the cities of Canopus and Herakleon in the same area were submerged, apparently due to liquefaction, following an earthquake between 731 and 743 BC. If something similar occurred to Atlantis situated at Pharos it might explain the shoals of mud reported by Plato and may even have been the reason for the erection of the famous lighthouse there, completed around 280 BC.
This lighthouse at Pharos took 20 years to build and is reported to have been as much as 450 feet in height, topped with a statue of Poseidon (or Zeus). It is claimed that there was also a furnace on top which, according to Robert Temple , suggested that some form of mirror reflected light out to sea. There is evidence from early writers that nocturnal sea travel was commonplace, so some system of beacons to assist this, would have been a natural development.
In a study of ancient lighthouses (pharology) by Ken Threthewey(a) , he indicates that there were probably precursors to the Alexandrian edifice, but that there is no archaeological evidence to support this contention. One suggestion is that altars, temples and latterly Christian churches frequently situated at the end of promontories may have functioned initially as navigational aids, keeping in mind that early Mediterranean seafarers preferred coastal hugging to open sea travel. In fact, I would think it strange if such locations were not used for beacons.
*Massimo Rapisarda & Marcello Ranieri have now published a paper(f) pointing to possible land based navigational aids, most likely, Phoenician, at the Sicilian promontory of Capo Gallo.*
Threthewey, a leading pharologist, published Ancient Lighthouses  in 2018. Furthermore, he has also published a series of eight lengthy papers on pharology on the academia.edu website(e) .
Another paper by Marco Vigano also investigates the subject of proto-lighthouses(b), furthermore a book review by Terrance M.P. Duggan draws attention to the use of the word ‘pharos’ as far back as the Homer’s time, centuries before the Alexandrine structure was built(c). Duggan has also written a paper on The Missing Navigational Markers(d).
A recent book, The Electric Mirror on the Pharos Lighthouse, edited by Larry Brian Radka, argues spiritedly for the use of electricity at Pharos!