This is a pleasant 18km (11 miles) or so walk which partly goes along woodland paths, drops back down to the Grand Union Canal then returns via Berkhamstead.
The walk is covered by Ordnance Survey Explorer Map no.181 with only the bit around Potten End not too clear however this is on The Hertfordshire Way which is signposted. Parking: From the A4251 at Northchurch take the B4506 which goes across the Grand Canal Union - continue uphill and parking is possible on a rough grassy section on the
right just where the B4506 takes a very sharp left bend - more or less at postcode HP4 1LP.
From the parking area and with the B4506 behind you head half-left up through woods - the main path is marked and has frequent wooden bollards.
Keep straight ahead at a track crossing and ignore cross paths to reach the B4506 again - go across this and the path then dips down and then climbs again to reach Northchurch Common. Follow the left hand side going alongside the Common to eventually reach Rail Copse at the far side. Just
inside the copse there is a footpath sign - go past this for about 20 yards and then turn right through the woods - the path follows close to the Common edge (which is always on the right). Ignore all cross and side-paths i.e. stay on the wide track which at times can be very muddy. Eventually the path comes out on a road - turn right and at the t-junction cross the road keeping straight ahead. The route is now marked The Hertfordshire Way path 33. This is a lovely woodland stretch which goes alongside Berkhamstead Common. On reaching Cold Harbour Farm the path
crosses a driveway and becomes a track - follow this to shortly reach a junction.
Take the path on the right which is still marked as The Hertfordshire Way Path 33 - keep on this yet again excellent stretch of woodland now with fields on the left. Near Brick Kiln Cottage the area ahead is quite open and then fairly soon reaches Berkhamstead golf course. The tree-lined path goes between the golf course and eventually reaches a road. Cross the road and take a path on the left which keeps to the edge of the greens to then reach
Nettleden Road. Turn right along the road for about 50 yards or so and then go left up an enclosed track (actually Grimm's Ditch) - this again passes between the golf course and then reaches a road.
Turn left and then shortly right to reach the village green and nice little pond at Potten End - this is about 5 miles from the start of the walk. At Potten End there is a lovely small church, old school house and also a small Public House called Martins Pond (named after the village green). Around the Pond there are several bench seats which are just
right for a sit and food/drink break however if it is cold and windy you could hide in the nearbye bus shelter which is covered.
From the pond walk on passing the pub to the far side of the village green and look for a path leaving the road on the right. This narrow path goes by a bowling green on the left and becomes very enclosed for a while - at the end turn right to soon reach a narrow lane. Turn left and follow this lane to a t-junction, turn right and then almost immediately left on a path which goes through a short
wooded section - then across fields to a lane. All of this part is well marked as The Hertfordshire Way. Turn left and follow the lane (Little Heath Lane) all the way down to reach the Grand Union Canal at Canal Bridge 145. (if you wish too you could at first go on past the bridge on up the lane to take a look at Bourne End Church).
Go down onto the towpath and turn left and now simply keep going along - the towpath does change sides at Turnover Bridge 143 - to eventually reach Bridge 142. As you near Berkhamstead it
may be of interest to know that there are a couple of canal-side Public Houses.
At Bridge 142 the option is to take a walk up into Berkhamstead Town to look at several of the old buildings in the High Street including a beautiful church and also some old school buildings. If you do this then when finished looking round head back from the church down Castle Street which takes you back to the canal towpath at Bridge 141.
Before continuing along the canal a further option is that you could cross over Bridge 141, turn left
then go under the railway bridge to take a look at the remains of Berkhamstead Castle which are on the right. There is actually very little to see at the Castle apart from low ramparts - see this Berkhamstead view
which shows a bit of the ruins plus the canal and the town itself.
Back on the Grand Union Canal towpath simply continue along enjoying the countryside and passing several canal locks to eventually reach Northchurch Lock at Bridge 139. Go under the bridge where there is not only the canal lock but an old pumphouse and also a convenient seat. To return to the original start go up onto the bridge, turn left and wander back uphill to reach the parking area.