02/07/2016 - I didn't think I'd get time to fit a visit to this stone in during my trip but luckily plans worked out well and on the last afternoon we found ourselves in Arisaig, good to go.
We started from the The Land, Sea and Islands Visitor Centre, a lovely small community run visitor centre in Arisaig. Well worth a look around and it has a nice shop. On display there is the Rhu Stone. Link below for more info. Very interesting.
It's a nice walk of about 4 miles to the stone and back on good tracks. Lovely for a sunny afternoon. The stone isn't hard to find, just off the track at NM 66917 84483. Over 80 cups on it. In the visitor centre there was a notice asking folk to stop putting coins in the cups as it was causing damage. Luckily the cups were empty today. Location is good with fine views of the surrounding hills.
If you have time, make the short walk on to the pebble beach at Camas Ghaoideil, it's a lovely spot for a brew and a sandwich.
Graeme C's 'Yorkshire Rock Art' site has the following quotation:
CUP MARKED STONE near Arisaig, PSAS vol 16 p397 - In the ground of Arisaig House there is a large block of stone with over eighty cup marks on its upper surface. A local belief connected with the stone is that an apprentice blacksmith could gain additional skill and strength in the craft by washing his hand in the water collected in the largest cupmark/basin on the stone, this act was to be performed at sunrise on the first of May.