This 8km track follows the Annalough Loop in reverse, starting and finishing at the car park of Fitzpatricks restaurant and bar. The reason for doing it in reverse was to cover most of the better terrain and ascent first before walking over the wet ground on the descent to the start. Slievenaglogh summit can be accessed from the track by heading over open mountain side any time after J 13113 08998, the summit is marked be a trig pillar at J 13679 08759. The reason I suggest not heading off before this point is that it is the site of a 1942 Plane Crash which claimed 15 victims. It was the most tragic crash in Ireland in the entire WWII/Emergency period, of which there were many, although despite this it is one of the lesser known crashes to have happened in our hills! The best account that I have found of it online is on the link below and I would suggest that you have a read of same before setting out for the hill.
http://www.skynet.ie/~dan/temp/al577/AL577_MOReilly.pdf
The legs of the plane can still be seen in the nearby bog, but I will leave it to those who read the article to ascertain where, this particular route does not go directly over them!

The majority of this track is on quiet country road and forest track, but after leaving the very brief road section on the northern side of the track the open mountain side track can be very wet in places and particularly so if you are leaving this track to make an ascent to the summit.

One other point of interest on this route comes very early on, although not as aesthetically outstanding as the many neolithic tombs in this area, the Rockmarshall court tomb is probably the oldest of them all! It is marked on the OSi map and the remnants of it can be found at J 12500 08000. While I'm mentioning neolithic tombs in the area, you really should check out Proleek Dolmen and it's impressive 40 tonne capstone which is a gentle stroll out the back of the grounds of the nearby Ballymascanlon hotel.