If you live near the holestone and are finding yourself with something interesting to do tomorrow (2oth March), then pop up and sit yourself at the holestone to test a theory.  The Holestone near Doagh, Co Antrim, seems to be aligned for its curve to let the setting equinox sun to roll down its back.

Tomorrow is the equinox and if you position yourself on the east side of the iron age standing stone with highest point of Donegore Hill aimed trough the hole in the stone then you might just see the sun roll down the curve of the stone.  I think you need to be there from about 5pm.