It was the summer of 1999 and, in a disused quarry in a forest in deepest Burgundy, a dozen or so incongruously attired figures were toiling away, hewing limestone blocks, chiselling oaken beams and hammering 6in nails.
The rough outline of what they were building was discernible, just: a perimeter wall a substantial 200 metres long and three metres thick; round towers, two large and two small, to mark the four corners; another pair flanking the main gateway.
