The grounds of Hertford Castle make a fine gathering and start point for the Cycle Orbital adventure.
The Family Friendly sections are Hertford to Stanstead St Margarets and Broxbourne to Waltham Abbey.
Hertford North is 1000m W of start and Hertford East 150m E of route at Hartham Common. Once through central Hertford, you ride offroad throughout on NCN61 and the Lee Navigation towpath.
Hertford and Ware 3 are attractive market towns. Between them pass the source of the New River 1.6, then there’s great bird watching at Amwell Nature Reserve 3.9. Stanstead St Margarets 5.1 has a pleasing waterfront.
At Feildes Weir lock (no5) 7 turn L for Spinoff 1 NE to Harlow on NCN1.
You have the luxury of two parallel routes through Lee Valley Park - towpath or NCN1; not only that, there are variants upon variants near Cheshunt or in Gunpowder Park. After Dobbs Weir lock 8.3 Arc 1 follows NCN1 as the preferred route as it detours to climb a hill (the last until Dartford!) in graded zigzags, passes through the wetland bird reserve (bird hides), then profits from an excellent offroad surface to Waltham Abbey 14.5.
Rejoin the Lee Navigation for Enfield Lock (R Spoke 1E Crew’s Hill, L Spinoff 2 to Epping Forest). There is plenty of towpath cycling to follow.