The Danevirke (or 'Danish work') is a massive earthwork built in 737Ad across 14 kilometres of the south of what was then their country - in fact they have now lost that area in battle to the Germans and the Danevirke is now inside Germany. However it is still a large earth rampart which crosses most of the peninsula just below Jutland. Archaeologists have done a dig in one section and have left this surface exposed to the weather. It contained interesting variations in the soil. The rampart, close to the excavation, was strengthened and enlarged in 808 and again in the 12th century. The Germans dug deep anti-tank trenches in it during WW2. This feature rather resembles Britain's Offa's Dike.