_Monuments_ 1 Forum 2 Argentina Temples 3 Cloaca Maxima 4 Pompey’s Theater and Portico 5 Imperial Fora 6 Altar of Peace 7 Augustus’ Mausoleum 8 Subterranean Basilica 9 Golden House 10 Coliseum 11 Cancelleria Palace 12 Domitian’s Stadium 13 Temple of Venus and Rome 14 Pantheon 15 Hadrian’s Mausoleum 16 Baths of Caracalla 17 Baths of Diocletian 18 Cemetery under St. Peter’s FIG. 12.11 Rome, Aurelian’s Wall, plan, with major Imperial monuments.] Richmond also found that in the phase of the wall identified as Aurelian’s by building materials and brick stamps, the workmanship differed sharply from one curtain to another. The inference from this was that various stretches were assigned to various gangs of workmen--mostly civilian, since the legions were needed in the North, and for Aurelian’s campaign against the Parthians in the East. These workmen belonged to the various city guilds, or _collegia_, some experienced in construction, some not, but all pressed into service in the emergency. Richmond distinguished the bottom twenty-four feet of the wall as the original phase. It was built of brick-faced concrete--that its bricks were often second-hand is inferred from the many Hadrianic stamps--surmounted by a gallery with loopholes outside and an open, bayed arcade inside, with a crenellated wall-walk above. Access to the wall was by the towers only; Richmond inferred that the planner aimed to keep excited and irresponsible civilians from interfering with defense, and the wall-detail from pilfering or philandering in the adjoining houses and gardens. In this phase the wall was plain, efficient, functional, simple, and uniform, built to a standard size and pattern. Its many gates show that there was no very formidable danger: the intent was to provide a barrier to shut chance bodies of undesirables out of the city as on far-flung frontiers structures like Hadrian’s Wall shut them out of the Empire.