The city now became extended in various ways. Industrious artizans established themselves by the river-side, and also on the other side of it (_trans Tiberim_). That this latter district was inhabited as a distinct quarter as early as the time of Augustus, is evident from the fact, that he made it a separate region; and this is at the same time a proof that it was thickly peopled. For although most other regions were of nearly equal extent, this one was comparatively small, which arose from the circumstance, that the great mass and the condition of its inhabitants required a more watchful vigilance of the police. This is the reason why that region was smaller than those in other parts. For opposite reasons, another region near the Porta Capena, in which the population was more dispersed, and which contained more palaces, was made unusually large. Suburbs existed as early as the Punic wars, and in the time of Marius and Sulla, the whole city was surrounded with suburbs; the ancient walls were then forgotten, and it seems that, for the purpose of removing all impediments of communication, even the gates were taken off their hinges. Along the river there was no obstacle, hence buildings were erected there under the Capitoline and Palatine.[11] It is commonly imagined that the whole district at the reach of the Tiber was called Campus Martius, but the Campus occupied only a part of it. At the foot of the Quirinal, too, buildings were erected, and all these enlargements may have narrowed the Campus Martius. In other parts the gardens were isolated, not forming a connected quarter. One suburb was situated at the distance of a Roman mile from the city, on the Appian road; it was even outside the Aurelian wall, which is still standing, and was called _ad Martis_. When the city had become thus enlarged, there followed the conflagration of Nero, the effects of which have not yet been made clear, but I hope some time to be able to give a satisfactory account of it. The Palatine, a part of Caelius and the district about the Circus were, perhaps, completely reduced to ashes; so also the Via Flaminia on the west of the Capitol; but other parts were less injured.