Hiya !

The pictures you are posting are very interesting - that barrow below Cheetham Hill, for instance - and the hills near Slipper Lowe. There is a webpage about a similar (but Welsh) pair just here ( http://www.megalithicsites.co.uk/twotumps.html ). Working backwards to where this pair are clearly visible from will lead to an undiscovered site. (It may be under houses or factories - I don't know the area - and there may be nothing left but it could show where there's other horizon stuff).

It's probably best to use the term 'perforated stone' for these strange standing stones and to reserve 'holed stones' for those that have wacking great holes - like that at Men-an-Tol and the Devil's Ring and Finger. The County Archaeology Unit class them as 'gateposts', little realising that they had a function previously - often those rectangular pierced ones are five Megalithic Inches across. It could be a coincidence.

The moonset, on Aug 16, should be spectacular from the Counting Hill row, in Smithills, if it's clear ...