Murus Gallicus that delimits an area of 135 hectares for a length of per battlement. It is estimated that construction of the wall required more than 10,000 cubic meters of wood, between 10,000 and 20,000 cubic meters of earth and about thirty tons of iron. The second wall, surprisingly outside the first, encircles an area of 200 hectares and was the subject of research beginning in 1992 for initial probing. This archeological research revealed that the battlement had had a height between four and five meters (13 and 16 feet) without its yet-unknown top (e.g., palisades or towers) and an identical depth, and was preceded by a ditch between 2 and 4 meters (7 and 13 feet) deep and between 6 and 10 meters (20 and 33 feet) wide. A study was conducted between 1995 and 2002 with many probes along with those by the University of Vienna. The researchers were able to ascertain that this battlement was a Murus Gallicus that had been dismantled in order to construct the inner wall. The dating, however, remains imprecise, and places this event during the 2nd century. These excavations also updated a postern to the level of Porrey, which is the only one currently known for Murus Gallicus type fortifications. The battlement is punctuated by about fifteen gates, including the famous Gate of Rebout (20 meters (66 feet) in width and 40 meters (131 feet) in depth). The gate of Rebout was the first location excavated by Bulliot, where he worked for nine weeks, and was the first site for new excavations from 1984 to 1986 which also studied the ditches adjoining the battlements. These excavations revealed five levels of different restorations, including a palisade from the Neolithic Era (dated with carbon-14). The latter has been the object of a reconstruction since 1996 which currently marks the entry into the old oppidum. At the present time, research has not been able to detect a trace of a method for locking the gate or a defensive device for it. Some hypotheses have advanced the idea of a double gate surmounted by a wooden guard tower like that of the Manching oppidum, but nothing has yet confirmed this. The recent research on the battlements, since 2005, has concentrated on a line of fortification downhill from the Gate of Rebout. Dating seems to indicate that this construction took place after that of the gate and