St Albans, GB
Beech Bottom Dyke, is a large ditch running for almost a mile at the northern edge of St Albans, Hertfordshire, England flanked by banks on both sides. It is up to 30 m (98 ft) wide, and 10 m (33 ft) deep, and it can be followed for three quarters of a mile between the "Ancient Briton Crossroads" on
the St Albans to Harpenden road until it is crossed by the Thameslink/Midland mainline railway at Sandridge. Beyond the railway embankment it continues, to finish just short of the St Albans to Sandridge road. This part is not accessible to the public.
Listen to the audio guide for Beech Bottom Dyke Free on WIP — starts by itself when you arrive, even with the screen off