In fact of course they were knocked together by a tribe of boozy Brits taking part in a totally useless exercise orchestrated by visiting aliens on an anthropological kick.
However, in defence of those boozy Brits smashed out of their primitive brains on cheap mead, they made rather a good job of it and bits of it falling down over the years had nothing to do with them putting in dodgy foundations.
The truth behind their slightly ruined state has been revealed in the newly published diary of Lady Caroline Lamb, who knew everybody and could never pass up a good party.
It seems that for the last millennia or so the land on which Stonehenge stands had been part of the ancestral estate of the Earls of Parsonsnose
The 23rd Earl, Earl Roscoe, had been well known for the wildest drunken parties in Regency England, and when almost sober was also a gentleman amateur astrologer.
As his usual guests were a rowdy bunch and had trashed his Manor House on several occasions, the Earl had taken to holding his parties outdoors by converting Stonehenge into a large tent by draping some spare canvas sails from HMS Victory over several stones and lintels.
Luckily, Lord Nelson was always ready to flog Navy stores for cash to support his affair with Lady Hamilton and only brought on the battle of Trafalgar because he needed some prize money from the sale of captured ships.
Earl Roscoe cast his horoscopes using a brass Navy telescope which he had bought from Lord Nelson.
The biggest damage occurred during the birthday debauch he threw for mad, bad, Lord Byron at which Lord Roscoe had promised to cast a horoscope for the birthday boy.
To get a good look at the conjunction of Venus and Mercury without having to move his ample posterior from his comfortably cushioned chair, he channelled his party guests' surplus energy into knocking over some inconvenient stones which obscured his line of sight.
Bashing about an ancient monument did not worry him much, as his business enterprises had already recycled half of Hadrian's Wall into the pig sties and the outdoor privies of most of Scotland.
Alas for Lord Byron - Lord Roscoe had forecast a 123 year lifespan and marriage to the Princess, later Queen, Victoria.
Little Vicky however wisely kept well clear of him, while Byron died young in the hills of far off Greece by what was most likely a smorgasbord of diseases of indulgence.
It seems Lord Roscoe, a self-made alcoholic, was never too certain which end of his telescope he was looking through anyway. He had successfully concealed his alcoholism from his rich and famous friends because they had never ever seen him sober and because his behaviour when sloshed was about the same as that which passed for normal for most of the gentry.