Barrows

I was watching a U-tube lecture on European archeology.  They excavated a huge barrow in England.  Built back in prehistoric times, before writing, all we know about then comes from archeology.  It was a big structure, half underground, half above ground.  These things are often described as graves.  On this barrow, they excavated and found the bones of forty individuals.  Forty?  Not many for a barrow that big.  The place was big enough to hold a 1000 graves.  Especially when you think how difficult it must have been to build such a place in the stone age.  Few workers, a poor hunter gatherer economy, no metal tools, not even shovels.  It must have required powerful motivations to build those barrows.
   Barrows are traditional described as grave sites.  That U-Tube lecture makes me think that the barrows served other purposes. Tribal gathering places, sacred places where shamans asked the god for good weather, good hunting and good luck.  Places where seers predicted the future.  We cannot know at this remove in time.  I.m thinking those few graves were the graves of a few exceptional individuals, priests, kings, shamans, mighty warriors, buried in the barrow to bring good luck, bring a friendly spirit, and make a sacred place more sacred.  We still do this.  Look at Westminster where the British bury their kings and scientists and soldiers.