During the Battle of Alésia, whose fortifications were partially reconstructed on the site of the MuséoParc Alésia, Julius Caesar reinforced the city's siege by having a series of traps built. The Gallic oppidum was surrounded by several lines of ditches at the bottom of which were fixed large branches tied to each other, whereas other ditches were filled with water. Staggered holes in which pointed stakes were placed were camouflaged by brush. Pointed branches were attached to the earth ramparts to make climbing the palisades harder.