To fully understand the city of Perugia, the marvellous fashion of its building, and the way in which its houses have become a part of the landscape and seem to creep about and cling to the unsteady crumbling soil, one should pass out into the country through one of its gates, and, rambling round the roads and lanes which wind beneath its walls, look ever up and back again towards the town. In this way only is it possible to understand what man can do with Nature, and how, with the centuries, Nature can gather to herself man's handiwork and make of it a portion for herself. Birds and beasts have built in this same fashion, but rarely except in Umbria have men. "The unstable quality of the soil on which Perugia is built," writes Mariotti, "has made strong walls and very costly buildings a necessity," and he goes on to point out the different and expensive ways in which the town has been bolstered up with solid masonry. The Etruscans were the first to recognise this necessity. They may have been a peaceful and a rather bourgeois set of human beings, differing in all ways from their combative successors, but they understood the science of building, and their walls, which encompassed only about one-third of the space covered by the mediæval town, remain a monument of splendid solid masonry wherever they can be traced. [Illustration: ETRUSCAN ARCH. PORTA EBURNEA] * * * * * The Etruscan walls are a marked feature of some Umbrian cities, and although it is rather the fashion to dispute their authenticity in Perugia, the bits which remain of them there are probably quite genuine. They have, however, become such a part of the mediæval and the modern town, and are often so embedded in later buildings, that without close study it is difficult to trace them; we have therefore marked their course in red on the map of the town.