Absolute classic, long over the moors lane, then though couple of forests and light wooded country with plenty of water and lots of gates as well, featured recently in a national mag has got very popular. Since close to the A494 and runs parallal to the Brithdir "rat run" which avoids Dolgellau plus on the route to other lanes as well, so expect this to be a morning or late afternoon run on the days out.
There is a series of lanes in the area, and as expected navigation is a nightmare, you'll cross many UCR's and forest tracks, its not to differcult, but not for wide trucks as the stone bridges will rip out your sides. Not too damaging however you might get a few straches as expected going though any forest.
It can be a long lane, about 4 "clicks", and can take about 1-2 hours, however the gates will slow you up as mentioned plenty of them and some narrow, north end starts @ SH813217, but you will need the "Knowledge" to know were to turn off, it heads west.
South side starts @ SH794172, again differcult to find its just a gate on the busy A470, its at the top of the hill , if coming from the west its hard to turn into the lane, if from the east easier but need to stop on the main road and cross. If doing south to north navigation is easier
link for the south end here
http://www.streetmap.co.uk/newmap.srf?x=279475&y=317280&z=3&sv=279475,317280&st=4&ar=Y&mapp=newmap.srf&searchp=newsearch.srf
