Not only were they before the use of metal why would thy have loads of moulds the same size? How would they use the ones that stand up? Try this one used for grinding herbs, potions, tinctures such as woad, hallucinogenic plants mushrooms, and other sacred herbs/plants. This for the horizontal and star patterns, for the vertical and/ or sources of “GOOD” water. They did use rocks/ pebbles in the holes to show stars (see Feaghna county Kerry aka rolls of butter) There is a picture in my Photos this is the main stars of Orion the hunter as seen over the hill in the distance. The brightness of the stars is shown by the size and depth of the holes. The stone in the middle is Phallic there are lots of alignments in this valley. I will try to add the photo and stars alignments to that site if anyones intrested
Snap