This was a complete surprise. Stopped off in Co. Tyrone to visit some old friends of the friend I was travelling to Donegal with. They just happened to know Mark Bailey the Director of Armagh Observatory who holds the key for Knockmany. He and his wife very kindly accompanied our small group up to the cairn which sits at the very top of a reasonably steep hill - commanding 360 degree views in all directions. Going inside the chambered cairn was a real thrill - my first close encounter with Irish rock art. Mark Bailey has the theory (a good one I should think) that the skies were once far more active in terms of comets and visibility that they appear to be now. And that the spiral shape with a 'tail' replicates a comet tail structure. We decided that the cairn was aligned north/south orientated due south towards Slieve Gullion and the Mournes. The cairn now has a clear glass covering and is not accessible without the key to the grill gate. However, most of the tomb can be seen quite well through the gate.