The full walk is a good 80 km (50 miles) long, but I restricted myself to those bits covered by Transport for London as in their web site page for the walk.
Transport for London's route headed south, starting at Waltham Cross and ends at either Trinity Buoy Wharf or Limehouse Basin, but I did it the other way round, starting at the Thames and heading north.
I also combined it with another walk, namely The Line, which is an outdoor sculpture trail that ends at the O2 Arena, but again I did it in reverse. The Lea splits into all sorts of channels around the old Olympic Stadium, and I spent some time exploring which were accessible.
The resulting segments were:
- Walk 1: O2 to Three Mills (8.1 km)
- Walk 2: Three Mills and Olympic Park (9.7 km)
- Walk 3: Hackney Marshes (11 km)
- Walk 4: Clapton Pond to Meridian Water (8.9 km)
- Walk 5: Meridian Water to Waltham Cross (11.7 km)
That was around 50 km in total. There was also a bonus walk of the:
- Walk 6: Greenway from the Olympic Park out to North Woolwich (11.8 km).
I'm tagging these with label "Lea Valley" so when these all the relevant posts are published you can find them by clicking here.
One thing should point out is the difference between the Lea and the Lee. Basically anything natural is called "Lea" - as in Lea River - while anything of human construction is called "Lee" - such as the Lee Navigation. See this post on Wikipedia.
Useful - if slightly out of date - post on the Londonist web site about the walk