Griffin Forest is another of the large, uniform plantations that aren't particularly interesting hiking routes, so they put cycle routes there. Cycling means that you get to see the occasional interesting feature without hours of walking down corridors of trees. There are a few lochans and craggy areas breaking up the forest, and it's an excellent area for wildlife, with hen harriers and crossbills two of the interesting bird species.
At the official car park marked on the map.
Moderate - no real technical challenge but good fitness is required.
The route is fairly level apart from the section west of Grandtully Hill, which is steep. This might influence which direction you choose!
Flies and midges can be a particular problem here, so be prepared, especially on an evening trip.