After another rediculously long midnight drive I parked up just a couple hundred yards from this cup and ring marked rock, and fell asleep almost imediately, three short hours later and the alarm went off, let the hunt begin .
Two or three miles south of St Catherines on the A815 turn left into forestry commision land, park here in sight of the road and walk up the track.
The track does two hairpin turns then straightens out, follow the path over two small streams and stop at the third, then either follow the stream downhill for 90metres like I did and not find anything, which is what the OS map and the Canmap map said to do, however after re-reading the details of the cup and rings, dont go west downhill but east uphill for 90metres, to be fair to myself I did go in both directions but spent so long in the wrong place that I ran out of time and had to abandon the search, it must be there somewhere.
Whilst tearing big sheets of moss off boulders looking for rock art I gained a new appreciation for moss and bare rock, mosses capability to completely cover everything in atleast a couple of inches of spongy carpet, and when removed from the rock it shines new and bright, blinking in the morning sun.
For anyone wanting to make another attempt on Tom Nam Clach here's what Canmore says....
Cup and Ring marked Rock, Ardgowan - A level shelf of rough outcrop, 13' x 7', 125 yds E of forestry road, 45 yds SW of hill top, is sculptured with 2 cups-and-two-rings, 4 cups-and-one-ring, and over 26 cups. Biggest diameter 11", deepest 2". Much weathered. Eight cups-and-rings were found in 1962
R W B Morris 1969; G Christian and E B Rennie 1962.
Cup and Ring marked Rock as described by Morris.
R W B Morris 1977.
This badly weathered cup-and-ring marked rock outcrop is situated about 90m E of a trackway and lies in a small clearing within a forestry plantation. It bears two cups with two rings, six cups with single rings and at least twenty plain cupmarks.
Visited April 1986
Definatley east of the track yet mappy says west, please dont say maps can be wrong.