Harolds Stones at Trellech, 'quite neatly directed toward the midwinter sunset' (Burl) makes you think they were probably upright when first placed there. Then again, I imagine Aveburys ditch was probably full of water, so...
Boscawen-Un :
' The stone leans towards the north-east sector of the circle where an arrangement of stones may represent an earlier, possibly contemporary cairn or cist. That this feature also pre-dates the circle is apparent in the spacing of the circle uprights at this point. When the circle itself was erected, the quartz stone was placed on the south-west side of the circle in alignment with the central stone and the cairn-like structure to the north-east... The south-west position of the quartz stone also marks the direction of the full moon during mid-summer.'
The Gorsedd association makes it tempting to imagine the stone as vital to activities at the circle at that time. Whatever they were.
'The Welsh Triads which date back to around the 6th Century AD record "Boskawen of Dumnonia" as being one of the "Gorsedds of Poetry of the Island of Britain".'
