I'm not aware of any actual existing Bronze Age monuments at these three wondrous sites...... however I'm continually struck by how Neolithic barrows and Bronze Age cairns were 'incorporated with care' within many Iron Age enclosures so I think it likely these hilltops were considered to possess some lingering supernatural power by Iron Age societies. Power the chieftains thought they might be able to appropriate for themselves. If this was the case folklore passed down through time surely held the key to such notions?