No. The Soma is very well documented.
We know that Alexander the Great died at Babylon in 323 BC. There is a bit of confusion in the sources about where he wanted to be buried, with various different wishes ascribed to him - one is Siwa in Egypt as the son of Zeus-Ammon (eg. Curtius); another is the implication that he did not want to be buried with Philip II at Aegae / Vergina ...
Either way, the funeral procession was making its way back to Macedonia (the modern Greek province, not the former Yugoslav republic sometimes called 'Macedonia') ... and then Ptolemy either hijacked the body or was given it, and Alexander the Great's body ended up in Egypt. Pausanias [1.6.3] says of Ptolemy:
He crossed over to Egypt in person, and killed Cleomenes, whom Alexander had appointed satrap of that country, considering him a friend of Perdiccas, and therefore not faithful to himself; and the Macedonians who had been entrusted with the task of carrying the corpse of Alexander to Aegae, he persuaded to hand it over to him. And he proceeded to bury it with Macedonian rites in Memphis, but, knowing that Perdiccas would make war, he kept Egypt garrisoned.First Alexander was buried at Memphis, then, at the latest under Ptolemy II, it was moved to Alexandria. The new tomb known as the 'Sema' seems to have been built by Ptolemy IV, and become a family funerary complex for the Ptolemaic dynasty. The term Sema can mean a burial mound, amongst other meanings (for example the more general 'tomb'), but the only description of it suggests a pyramidal roof. Strabo used the term 'Soma' not the 'Sema' used in later sources - this tends to be amended to the latter in editions, but perhaps this earlier name "the body" may well have been the original name of the structure, as it seems to be an 'error' made by other ancient sources.
At some point a Ptolemy melted down the gold sarcophagus as he was short of funds, replacing it with a glass sarcophagus. A bit of building was done, but it is well attested as having been there throughout the Roman period.
This is a nice neat simplified summary from a reputable popular archaeology magazine:
The Elusive Tomb of Alexander - Archaeology Magazine Archive:
The literary tradition is clear that the third and last tomb was located at the crossroads of the major north-south and east-west arteries of Alexandria. Octavian, the future Roman emperor Augustus, visited Alexandria shortly after the suicide of Cleopatra VII in 30 B.C. He is said to have viewed the body of Alexander, placing flowers on the tomb and a golden diadem upon Alexander's mummified head. The last recorded visit to the tomb was made by the Roman emperor Caracalla in A.D. 215. The tomb was probably damaged and perhaps even looted during the political disturbances that ravaged Alexandria during the reign of Aurelian shortly after A.D. 270. By the fourth century A.D., the tomb's location was no longer known, if one can trust the accounts of several of the early Church Fathers. Thereafter, creditable Arab commentators, including Ibn Abdel Hakam (A.D. 871), Al-Massoudi (A.D. 944), and Leo the African (sixteenth century A.D.) all report having seen the tomb of Alexander, but do not specify its exact location.The key development in the Roman period is that the tomb was closed up by Septimius Severus. Cassius Dio 76.13:
He inquired into everything, including things that were very carefully hidden; for he was the kind of person to leave nothing, either human or divine, uninvestigated. Accordingly, he took away from practically all the sanctuaries all the books that he could find containing any secret lore, and he locked up the tomb of Alexander; this was in order that no one in future should either view Alexander's body or read what was written in the above-mentioned books. So much, then, for what Severus was doing.Before people start leaping to conclusions that Severus had the Sema walled up, and make links to the ancient walling up of the gateway of Amphipolis ... he only ordered the tomb closed up. We know that because his son Caracalla was able to visit the tomb according to Herodian IV.8:
Leaving the temple for the tomb of Alexander, he removed there his purple robe, his finger rings set with precious gems, together with his belts and anything else of value on his person, and placed them upon the tomb.This passage is reiterated by John of Antioch writing in the 7th century, where the implication is that the tomb was still around. Much can be written about Caracalla's nutty obsession with Alexander the Great and of himself as the new Alexander, but when he sacked Alexandria he spared the tomb.
Leo Africanus was in Egypt in 1517. Alexander the Great, known as Iskander in Arabic, was an important figure in Muslim universal histories, so claims that his tomb was destroyed by the Muslims are propaganda. His tomb also does not seem to have been destroyed by Christians during anti-pagan rampages, nor is there clear evidence it was in AD 270. The problem is that in the Ottoman period - and Leo was in Egypt during the Ottoman conquest - there at some point became two rival sites shown to visitors as the tomb of Alexander in Alexandria. This may well reflect the early and the later Ptolemaic tombs in the city, or could simply be an example of tall tales spun to tourists - the more 'popular' of these was the Byzantine church of St Athanasius which later became the mosque of Attarine.
Although we've become used to rulers and emperors becoming living gods, it was pretty revolutionary for Alexander to be considered a living god. The one way his tomb differed from his ancestors, contemporaries and immediate successors was that it was a heroon and had a cult. The Persian satrap Mausolus a generation earlier had had a tomb with a hero-cult, but that was a dodgy foreign practice. The only contemporary of Alexander to be given a heroon and cult after his death was Hephaestion, and that was at the orders of Alexander himself; there is only one votive relief from Pella to the Hero Hephaestion that I am aware of, and no real evidence that his 'cult' survived the death of Alexander himself.
There have been a variety of recent rumours that Alexander's body was later moved to Siwa (unsupported by any source or evidence), or that it was confused with St Mark's and taken to Venice (ditto).
The new obvious 'conclusion' a few people have leapt to is that Alexander's body was 'secretly' later moved to Amphipolis. To point out the obvious, if Alexander's body had been moved in the Roman period then he probably would have been in a Roman period structure not an early Hellenistic one.
Perdiccas as regent had clearly planned to bring Alexander's body back to Macedonia, but he was unable to do so. If Perdiccas had chosen the burial site, he would almost certainly have chosen the Argead family cemetery of Vergina to strengthen the claim to the succession of the child Alexander IV for whom he was regent. The same argument would apply to Antipater. If Alexander III had planned his own tomb in Macedonia, he could have chosen another site.
It is possible that Alexander's 'original' Macedonian tomb was finished, and the hope was that his body could be recovered from Egypt at some point, in the same way that centuries earlier Athens under Cimon had regained the bones of Theseus. But again, this is pure conjecture.
Either way, the original location of Alexander the Great's planned tomb in Macedonia can for now only be pure speculation.
No-one who has seen the evidence excavated at Amphipolis has claimed he was buried there. I'm the only idiot who's said it could have been intended for Alexander but not used for his burial.
(Apologies for the hurried post, but ... the speculation was getting ridiculous).
For those who want to read up, I highly recommend:
Andrew Stewart, Faces of Power: Alexander's Image and Hellenistic Politics, Berkeley 1993, pp. 214ff (available on Google books here).
For those with JSTOR access, this article has a good summary of the arguments over the burial and some of the history of the tomb:
Andrew Erskine, Life after Death: Alexandria and the Body of Alexander, Greece & Rome Vol. 49, No. 2, Oct., 2002, pp. 163 ff.