Throughout history, walls have been constructed as part of nations' and kingdoms' defensive structures to keep barbarian hordes, marauding rebels, and recalcitrant tribes out of defined geographic areas. Defensive walls were usually constructed by fairly advanced and sophisticated peoples, such as the Romans and Chinese, with varying degrees of success. Of course, the most famous of all defensive walls in the world is the Great Wall of China, which is actually a series of walls and forts built over the span of several centuries. The Chinese built the Great Wall of China, and several others, primarily to keep invaders from the north, such as the Mongols, out of their land, or at least to slow them down as they fled north after raids. The Romans also built spectacular walls, most notably the Antonine Wall and Hadrian's Wall. The purpose of those walls was to set the northern limit of the Roman Empire at approximately the modern border of England and Scotland, and, like the Great Wall of China, it was intended to keep out or slow down marauding barbarian tribes from the north.
The Great Wall of China is perhaps the wonder of the world that has most captured the human imagination, and as the quotes about it indicate, the wall has acquired special significance even outside of China. The places and ways in which it has taken hold vary greatly, but one thing is certain: the Great Wall of China is as amazing as it is mysterious, and it's as mundane as it is magical.
The Romans were master builders, and much of what they built has stood the test of time. Throughout their vast empire they have left grand structures, from the Forum and Pantheon in Rome to the theatres and hippodromes of North Africa and the triumphal gates in Anatolia and France. Wherever they went, the Romans built imposing structures to show their power and ability, and one of their most impressive constructions was built on the northernmost fringe of the empire.
