This was the Roman Empire's version of the Great Wall of China. It worked well, and was used for 288 years. When it was built, Britain was an outer province of Rome and vulnerable to attack because of its distance from the heart of power and might. Much like the Chinese, Rome sought to keep "barbarians" from the north at bay. The wall was designed to run 99-miles along the British coast to Bowness-on-Solway, and east to Wallsend-on-Tyne. The same way towns today spring up along freeways, settlements mushroomed along the route of the wall as entrepreneurs sought to take care of the needs of the Roman soldiers manning the ramparts.. Not all of it was built. Reflecting the Roman leanings toward regimen and uniformity the wall was built in a very methodical pattern. The wall was at least eight-feet wide, at least 12 feet high, and lined with a culvert. There were fortifications every mile, and two guard towers evenly spaced between. All of these measures are in Roman feet, not the feet we know today.