I quite randomly followed the Grand Union Canal up to Horsenden Hill from Alperton a few days ago. Horsenden Hill was rather similar to Chapel Bank with its wild-flowers, butterflies and grazing cattle. The views from the top of the hill were stunning, you could see all the way to the North Downs, Surrey, and the whole of West London! I'd def recommend a trip. Plan on going back soon and walking to Harrow-on-the-Hill... (my last grand union canal adventure: http://sysprints.blogspot.co.uk/2012/10/a-trip-to-aylesbury.html)