In Europe the custom of the walled city continued as evidenced by sites such as the Oppidum of Manching (located near modern-day Ingolstadt, Germany) which was a 3rd century BCE Celtic community of the Vindelici tribe. The Roman city of Lugo in Galicia, Spain was surrounded by enormously thick walls considered utterly impregnable. The most famous wall of antiquity in Europe, however, is Hadrian's Wall in Britain. The Roman Emperor Hadrian (76-138 CE) grew tired of incursions into the Roman provinces in Britain and so, in the year 122 CE, began building a wall across the northern border of Roman Britain to separate it from the invading Pict tribes much in the same way that Shulgi built his wall almost two thousand years earlier to keep out the Amorites (as with the Great Wall of China and the Anastasian Wall). It took six years to build, stretched for 80 miles (128 kilometres) across the border between what is now England and Scotland and was, at points, over nine feet wide (2.7 metres) and twenty feet (6 metres) high. It was fortified at towers along the way and served as a symbol of Roman military might and power. The later Antonine Wall (begun in 142 CE under the reign of the Roman emperor Antoninus Pius) stretched 39 miles (63 kilometres) between the Firth of Forth and the Firth of Clyde and was constructed for the same reason as other such walls: to protect the known region of the inhabitants from the incursions of the `other' whom they regarded as dangerous barbarians.