The West Highland Way
Milngavie to Fort William
95 Miles
I did this walk two years after doing the Coast-to-Coast. Although only half as long I'd say it was about twice as demanding, as testified by my subsequent hardships ;). The detailed route map has been borrowed from the official site of the West Highland Way.
See the map below it to locate the wider geographical area.
So now, adjust your shoulder-straps, gird your loins, and
follow me...