Another example of an Italian town-plan, from the same date and district as Turin, is supplied by Augusta Praetoria, now Aosta, some fifty miles north of Turin in the Dora Baltea Valley, not far from the foot of Mont Blanc.[77] Aosta was founded by Augustus in 25 B.C. on a hitherto empty spot, to provide homes for time-expired soldiers and to serve as a quasi-fortress in an important Alpine valley. Its first inhabitants were 3,000 men discharged from the Praetorian Guard, with their wives and children; its population may have numbered at the outset some 15,000 free persons, besides slaves. The town, as it is known to us from excavation and observation, formed a rectangle 620 yds. long and 780 yds. wide, and covered an area of about 100 acres (fig. 16). The walls formed sharp right angles at the corners, as at Turin. Within the walls were an amphitheatre, a theatre, public baths, a structure covering nearly 2 acres and interpreted as a granary or (perhaps more correctly) as a cistern,[78] and private houses as yet unexplored. Beneath the chief streets were sewers, by which indeed these streets were mainly traced. [77] C. Promis, _Antichità di Aosta_ (Torino, 1862), with plan, plate 3, dating from 1838; _Notizie degli Scavi_, 1899, p. 108, with a later plan, but lacking a scale; Nissen, _Ital. Landeskunde_, ii. 171. [78] Durm _Baukunst der Römer_, p. 458. [Illustration: FIG. 16. AOSTA] The whole was divided by a regular network of streets into rectangular blocks. According to the latest plan of the site, there were sixteen blocks, nearly identical in shape and averaging 145 x 180 yds. (5-1/2 acres). That, however, is an incredible area for single house-blocks, and it is to be noted that Promis shows two further roads (A, A in fig. 16). If these are survivals of other such roads, Aosta may have contained thirty-two oblong 'insulae', each nearly 220 x 540 ft., or even sixty-four smaller and squarer 'insulae', measuring half that size.[79] Four gates gave entrance; those in the two longer sides which face north-west and south-east, are curiously far from the centre and indeed close to the south-western end of the town. It is, of course, impossible to determine, without spade-work, which of the recognizable buildings of Aosta date from the foundation of the place in 25 B.C. But the general internal scheme and the symmetrical and practically 'chess-board' pattern of streets must date from the first foundation.[80] [79] Promis, p. 140; his plan has no proper scale. There seems no decisive evidence and the modern streets of Aosta do not help us.