A fine article here from irisharchaeology.ie on the 'Sacred Trees in Early Ireland'.
This part caught my eye as it refers to a site about 6 miles fro my own house.
'Craebh Tulcha', is the modern day townland of Crewe, on the road between Lisburn and Glenavy, a few miles inland from the Antrim shore of Lough Neagh (but the Loughshore was once much closer, until the boggy land was drained).
Indeed, this hill was once one of the most notable royal sites in Ireland, prominent in the Annals, and Brian Boru is recorded as having been hosted here.
Now within the modern boundary of Lisburn City Council, Crewe Hill, as an important heritage site, is invisible to tourist and local alike. It just goes to show, if you wait long enough, nothing stays sacred for ever.