They recently found a pit zone alignment (also known as 'Caesar's lillies' from the siege of Alesia) on the island of Funen. This is quite special, as these structures were previously only known from a specific area of Northwest Jutland. Their occurrence outside of this area suggests that this type of fortification might have been more widely known across the barbarian world. I don't know what the date for them is at this site, but I wouldn't be surprised if it's somewhere in the Later Roman Iron Age. I think from now on archaeologists should be more aware of these kind of shallow features (they were originally only dug to about 30cms depth), and expect we will find more of them in the future.