Of the interior buildings of the town little is known. The Forum perhaps stood near the present Palazzo di Città, and the Theatre was traced in 1899 in the north-east corner of the town, occupying apparently, a complete insula;[74] of the private houses nothing definite seems to be recorded. [74] _Notizie_, 1903, p. 3. But the street-plan has survived intact, except in two outlying corners. The town was divided up into square or nearly square blocks, of which there were nine counting from east to west and eight from north to south. Most of these 'insulae' measured about 80 yds. square.[75] A few were larger, 80 x 120 yds.; these were ranged along the north side of the street now called Via Garibaldi (formerly Dora Grossa), which represents the Roman main street between the east and west gates--in the language of the Roman land-surveyors, the _decumanus maximus_. This street cut the town into two equal halves. The other divisions of the town were no less symmetrical. But, as there were nine 'insulae' from east to west, the main north and south street could not bisect the town. Indeed, the south gate seems to have had five house-blocks west of it and four east of it, while the Porta Palatina stands further west, with six blocks on the west side of it. The north and south gates, therefore, are not opposite.[76] Whether this was the original plan is not clear, nor is the age of the surviving walls and gates quite certain; the bonding courses in some of the masonry of the walls does not seem Augustan. But the street plan may unhesitatingly be assigned to the first establishment of the town, about 28 B.C. Since, it has been extended far beyond the Roman walls. Nearly all modern Turin has been laid out, bit by bit, in imitation and continuation of the original Roman lines. [75] An insula is mentioned in _Notizie_, 1901, p. 391, which measured 74 x 80 metres. It is likely that there were small unevennesses in the ancient as there are in the modern house-blocks. The 'insulae' which abutted on the town-walls are represented to-day by unduly large blocks, oblong rather than square, but these latter contain not only the areas of the Roman 'insulae' in question, but also the space between them and the town-walls and the lines of the wall themselves (p. 77). [76] This failure in symmetry recurs in one or two other Roman towns as probably at Timgad (p. 109) and at Cologne (E. and W. gates), at Silchester and Caerwent, but it may sometimes be the result of alteration. Occasionally it appears in military sites (Ritterling, _Lager bei Hofheim_, p. 29 _note_). It is presumably a mere matter of convenience; no superstition attaches to it such as that which led the Chinese not to put their gates opposite each other (p. 148). [Illustration: FIG. 15. TURIN. FROM A PLAN OF 1844] _Aosta_ (fig. 16).