#6: Berkhamsted Circular
There are a couple of walking options on the Chiltern Area of Outstanding Natural Beauty website, but I recommend the 13.6km (8.5 mile) 'Southern Circular'. The walk crosses Berkhamsted Common and goes up into the Ashridge Estate.
You can extend the walk as far as 27km if you want to, or do an intermediate walk by ending at Tring railway station. Another option would be to drop down to the canal and walk back to Berkhamsted. A shorter walk is provided by this 6.5km circular walk from the centre of the town (add another 1km from the railway station along Bridgewater Road if you are coming by train).
Find out more about walking from Berkhamsted station.