Between 2012 and 2015, an excavation and two tests were carried out inside the oppidum of Vermand, near its northwestern entrance. The excavation of Place Blanchard revealed a dense occupation from the beginning of the Early Empire, situated around a vast defensive ditch 10 m wide by 5 m deep. Filled in around 30 BC, it is parallel to the north-west/south-east oriented road that crosses the oppidum. A cellar, a moat, stratified levels and a pit containing more than 1,700 fragments of honeycomb bear witness to a phase dating from the 20s to 10s bc, before a culvert was installed on the top of the ditch fill. This first phase ends at the beginning of the 1st century AD. The site was reoccupied from the end of the 3rd century. A new ditch, of reduced dimensions, was dug in the fill of the first ditch, then was filled in during the following century. A pit-house, a well and many pits show continuity until the middle of the 5th century. The construction site delivered almost 600 coins. In addition to a probably protohistoric ditch, the testing at 12 Grande Rue confirmed the presence of activity from the Late Empire, including traces of an artificial defensive glacis that defended the stronghold. It was formed by a layer of chalk blocks, deposited and compacted on the silt, with a view to rectifying the natural slope. The main discovery is a quadrangular enclosure, delimited by ditches more than 4 m wide and almost 3 m deep, whose internal surface was 53 m by 40 m. The southwestern ditch has an interruption of more than 6 m, thus opening access to the enclosure. Inside, along the ditches, a strip of land more than 7 m wide, with no structure, may have contained the spoil from digging the ditches, thus forming a bank. The excavation discovered a portion of road and some yard or roadside levels as well as two potter’s kilns. The hypothesis put forward is a fortress made of earth and wood from the Late Empire with an access to the southeast. The fortification has a practical location at the highest point of the oppidum, protecting the road that pass nearby as well as its northwest entrance. The testing of the Place de l’Hôtel de Ville has revealed several structures from the Late Empire and what is interpreted as the edge of the northeast escarpment of the oppidum.