The heart of Lydford is surrounded by a Saxon Bank upon which stood a wooden palisade wall. This was built in the 10th century when Lydford was turned into a Burh by Alfred the great to protect the people living in the area. The idea was that in the event of attack, local people could flee to safety within the walls until reinforcements could arrive. Threats at the time were from Viking raiding parties. You can walk around the town banks and there are information boards showing how it once looked.
Although Lydford has now expanded outside of its banks, they are almost perfectly intact and it is a rare find to see them so well preserved.