In reply to girlymonkey:
Don't think the one at Bracklinn Falls is the one you meant. That one is indeed amazing, and useful for a variety of bike routes in the area. However, the bridge that was at Arievuriardoch and had been swept away a few years ago has recently been replaced with a brand new - but bog standard - bridge, which is part of the infrastructure for the hydro scheme. If heading for Glenartney you can either stay on the new road to the cottage and then the original track back to the north east or you can blast directly up the wet moor to join the track there.