<p>Rome’s oldest and largest <i>circus</i>, a hairpin-track designed for chariot racing, situated in the valley between the *Palatine and *Aventine (*Vallis: Circus Maximus) near the *Forum Bovarium. Often simply called ‘the Circus’ (e.g., Suet., <i>Iul</i>. 39.2, <i>Aug</i>. 43.2; Varro, <i>Ling</i>. 6.20), the Circus Maximus was an important venue for public entertainments, which included wild-beast hunts (<i>venationes</i>), mock battles, and athletic contests (i.e., running, boxing, wrestling) in addition to equestrian events (Humphrey 70-71). Roman tradition credits the Tarquins with founding the Circus (Livy 1.35.8; Dion. Hal., <i>Ant</i>. <i>Rom</i>. 4.44.1), but the structure, which had been modestly built up in the 2nd c. B.C., only achieved its definitive form under Julius Caesar and Augustus (Ciancio Rossetto, <i>LTUR</i> 273). Though little archaeological evidence remains from the Augustan Circus, detailed literary accounts, especially that of Dionysius of Halicarnassus, allow a relatively reliable reconstruction of the monument (see fig. 9).</p> <p>Caesar inherited a circus with an already well-defined race course: 12 starting gates (<i>carceres</i>) stood at the Forum Bovarium end (Livy 41.27.6; Humphrey 136-37), two turning posts (<i>metae</i>) were fixed within the track and their axis was adorned with statues set on columns (Livy 40.2.2; Obsequens 5); in the Republican period, there was no continuous central barrier wall (probably not erected until the 2nd c. A.D.: Humphrey 292-93). At an early point, the *“Cloaca Circi Maximi” had been installed to drain the valley floor and thus provide an area suitable for racing (Humphrey 67). The starting gates themselves were unroofed, wooden stalls with an arcaded, tufa façade facing the track (Suet., <i>Claud</i>. 21.3; Dion. Hal., <i>Ant</i>. <i>Rom</i>. 3.68.1-4; Humphrey 133-34, 150). Each gate had a pair of wooden doors, which were simultaneously opened ‘by a single rope’ at the start of the race (Dion. Hal., <i>loc</i>. <i>cit</i>.). A set of ova (<i>eggs</i>) used to count laps stood in the track near the <i>carceres</i> where they were readily visible to the charioteers (Humphrey 71, 265). Before Caesar’s modifications, most spectators sat in wooden stands erected along portions of the long sides of the Circus; limited stone seating was reserved for the élite (Humphrey 68-70). An arch erected by L. Stertinius in 196 B.C. is often placed at the SE end of the Circus on the spot that would later mark the center of the semicircular stands; however, this monument is known only to have stood ‘in the vicinity of the Circus’, <i>in Maximo circo</i> (Livy 33.27.3-5; Ciancio Rossetto 1987, 44; Humphrey 100 suggests the arch may have stood near the <i>carceres</i> and Forum Bovarium); given the vagueness of Livy’s description, the arch cannot be indicated on our rendering.</p> <p>Several ancient cults native to the valley were honored within the circus. Near the first turning post (<i>primae metae</i>, at the SE end of the track) was an underground altar belonging to the archaic deity Consus (Dion. Hal., <i>Ant</i>. <i>Rom</i>. 2.31.2-3; Tert., <i>De spect</i>. 5, 8; Ciancio Rossetto, <i>LTUR</i> 322; Humphrey 61-62). The shrine of *Murcia (<i>sacellum</i>: Varro, <i>Ling</i>. 5.154) stood within the track near the <i>primae metae</i> on the Aventine side. The Temple of *Sol rose within the seating area on the Aventine side of the Circus, just opposite the finish line; it was to Sol that the Circus as a whole was consecrated (Tert., <i>De spect</i>. 8).</p> <p>In 46 B.C., Caesar enlarged the Circus to its canonical, breathtakingly-large dimensions: 3.5 stades long and 4 plethra wide (Dion. Hal., <i>Ant</i>. <i>Rom</i>. 3.68.1-4; Pliny, <i>NH</i> 36.102; c.650 x 125 m, Humphrey 75; c.621 x 118 m Ciancio Rossetto 1987, 43). Concurrently, he extended the stands flanking the long sides and added seating around the SE semicircular end, so that three sides of the arena were enclosed by a continuous ring of seating; these additional stands raised the capacity of the Circus to c.150,000 spectators (Dion. Hal., <i>loc</i>. <i>cit</i>.). To protect viewers during the <i>venationes</i>, Caesar installed a 10-foot-wide water canal (<i>euripus</i>) between the seats and the track (Suet., <i>Caes</i>. 39.2). These Caesarian changes were thought to have been Augustan by Cassiodorus (4th c. A.D., <i>Var</i>. 3.51), and in fact Augustus may have completed the building project planned and initiated by his adoptive father (cf. *Forum Iulium, *Curia Iulia; Humphrey 73; Ciancio Rossetto 1987, 40).</p> <p>In the Augustan era, several monuments were added to the Circus. In 33 B.C. Agrippa erected the famous set of 7 dolphins and a second set of <i>ova</i>, both along the axis of the <i>metae</i> (Dio. Cass. 49.43.2); these were used, like the original set of <i>ova</i>, to count laps but their central positions allowed spectators easily to view them (Humphrey 260-65). A severe fire in 31 B.C. (Dio. Cass. 50.10.3) caused Augustus to restore the Circus; perhaps this was the opportunity for him to monumentalize the *Pulvinar ad Circum Maximum (<i>RG</i> 19: <i>feci</i>), a templar ‘box’ reserved for statues of the gods located in the seating area along the Palatine side. In 10 B.C. Augustus dedicated an Egyptian obelisk to the sun-god Sol at the mid-point between the two <i>metae</i> (*Obeliscus: Circus Maximus; Humphrey 269-71). Often specific games or <i>venationes</i> called for special, impermanent, additions to the Circus; multi-storey pavilions and towers were erected in the arena during animal hunts (Humphrey 266), and it is possible that a temporary wooden barrier wall was erected between the <i>metae</i> for chariot races (Humphrey 292).</p> <p>Dionysius of Halicarnassus provides detailed information regarding the seating and exterior of the Augustan Circus Maximus (<i>Ant</i>. <i>Rom</i>. 68.1-4). The <br /> sloped stands were divided into three tiers, the lowest worked in stone and the upper two in wood (Dion. Hal., <i>loc</i>. <i>cit</i>.). The seats were cramped, and the tiers were separated by iron grilles (Ov., <i>Ars Am</i>. 3.2.63-64). Along the exterior of the Circus ran a one-storey portico with access-tunnels, stairways to reach the upper-level seats, and shops housing food vendors (Cic., <i>Milon</i>. 65), fruit sellers (<i>CIL</i> VI 9822), even astrologers and fortune-tellers (Cic., <i>Div</i>. 1.132; Hor., <i>Sat</i>. 1.6.113-14); some <i>tabernae</i> had second-storey living-quarters (Dion. Hal., <i>loc</i>. <i>cit</i>.).</p> <p>Traces of <i>opus reticulatum</i> walls belonging to the Caesarian–Augustan Circus are preserved at various points along the Palatine side of the <i>cavea</i> (Ciancio Rossetto 1987, 40). Recent excavations in the SE hemicycle recovered <i>opus reticulatum</i> substructures of the stands; Ciancio Rossetto interprets the finds as a series of three spaces (1987, 40-42): closest to the arena were low vaulted rooms with a thick rear annular wall which supported the first tier of stone seats (see also Humphrey 74), in back of these ran an interior ambulatory, and on the exterior elongated <i>tabernae</i> (shops) alternated with access stairs and tunnels. These finds correspond nicely to Dionysius’ description (Ciancio Rossetto 1987, 43; ead., <i>LTUR</i> 273).</p> <p>Our map is the first published reconstruction of the Augustan Circus Maximus (the Berlin Model does represent it, but erroneously includes a central barrier wall and a large honorary arch in the SE end). Given the limited archaeological evidence, a number of assumptions and hypotheses underlie the representation. The irregular shape of the arena, including the characteristic jog on the Aventine side designed to ensure a fair start, is extrapolated from post-Augustan ruins and their representation on the Severan Marble Plan (following Humphrey fig. 54). The two <i>metae</i> are neither shown on the Marble Plan nor archaeologically known, so their location remains hypothetical; our reconstruction favors Humphrey’s thesis that they were c.335 m apart (Humphrey 124-25). Archaeological evidence for the <i>carceres</i> (two stalls were excavated in 1903, see Humphrey 124-25) fixes their location with some certainty. More recent excavations have confirmed the position of the edge of the <i>euripus</i> (Ciancio Rossetto 1987, 44); from this fixed point, its course is extended along the three sides of the arena at the width specified by Dionysius (10 Roman feet, 2.96 m). While Ciancio Rossetto’s excavations helped clarify the form of the <i>cavea</i> substructures, the extant remains proved insufficient to determine the full depth of the Augustan stands, and thus an estimated figure of 28 m has been used for our reconstruction (Humphrey 74; c.30 m: Ciancio Rossetto, <i>LTUR</i> 275). Further, it has been assumed that the stands were of a uniform depth on all three sides. Finally, the Augustan restorations in the wake of the severe fire of 31 B.C. as well as his numerous additions justify rendering the Circus in the silver gray denoting an Augustan monument.</p>