The original 7.96 km circuit followed the undulating terrain of São Paulo's southern suburbs rather than being levelled into a flat venue. This gave the lap a roller-coaster quality, with significant elevation changes throughout and no two consecutive corners at the same gradient. Cars ran counterclockwise, which is unusual and places sustained lateral loading on drivers' necks in the opposite direction from most circuits on the F1 calendar.
The long layout included three extended straight sections and nine fast curves that have since been lost, along with the corners retained in the shortened post-1990 version. These original fast sweepers were taken at sustained high speed and demanded precision over bumpy asphalt under continuous lateral load. The circuit's surface was notably rough — BBC commentator Murray Walker described it as "appallingly bumpy" during the 1980 race, by which point the ground-effect cars of the era found the undulating surface barely manageable. The combination of high speed, irregular surface, deep ditches, embankments, and limited barrier protection classified the original layout as dangerous even by the standards of its time.
The sections retained in the post-1990 short circuit include the famous Senna S entry complex, the Curva do Sol, the Reta Oposta straight, and the long uphill sweep through Subida dos Boxes. The original layout extended these with the three long straights and faster, more open corners that were judged too hazardous to continue using as Formula One safety standards rose through the late 1970s.
Formula One first raced at Interlagos in 1972 in a non-championship event won by Carlos Reutemann. The Brazilian Grand Prix joined the World Championship calendar in 1973, with the inaugural race won by Emerson Fittipaldi, a São Paulo native and defending world champion who gave the home crowd a victory on home soil. Fittipaldi won again in 1974. Brazilian driver José Carlos Pace won his only Formula One race at Interlagos in 1975 — the win that would later be commemorated when the circuit was officially renamed Autodromo José Carlos Pace in 1985 after Pace died in a plane crash in 1977.
The Brazilian Grand Prix moved to Jacarepaguá in Rio de Janeiro in 1978 when the original Interlagos layout was judged to require safety investment, and stayed there while a shortened and rebuilt circuit was prepared. The 1979 upgrade extended the pit lane past the first left-hand turn and narrowed the corner entry, but the full rebuild that reduced the circuit to its modern 4.3 km form did not take place until 1990.
The final Formula One race on the original layout came in 1980. Drivers including defending world champion Jody Scheckter raised formal objections to the circuit's safety, citing the bumpy surface, inadequate barriers, and the hazards posed by the deep ditches and embankments flanking parts of the track. The race proceeded but the event did not return to Interlagos for a decade.
Unlike many famous circuits, Interlagos is situated at moderate altitude — São Paulo sits around 760 m above sea level — and while this does not produce the extreme altitude effects of Mexico City, the local climate plays a defining role in the character of events. The circuit sits in a region of São Paulo known for rapid weather changes, with tropical downpours capable of transforming dry conditions to standing water within minutes. This unpredictability became part of the circuit's identity and remained a feature of the modern venue.
The original Interlagos layout is remembered as one of the great lost circuits of Formula One's classic era: a long, fast, physically demanding track that ran through genuinely hilly terrain and placed an extraordinary workload on both cars and drivers. Its bumpy surface and elevation changes produced racing that tested chassis setup, driver stamina, and mechanical reliability simultaneously. The three Formula One world champions who won there in the 1970s — Fittipaldi, Fittipaldi again, and Pace — all had deep personal connections to São Paulo, adding a human dimension to the circuit's history that extended beyond technical attributes.
In sim racing, the 1970 Interlagos layout offers an experience unavailable on the modern circuit: the three long straights, nine additional fast corners, and the rougher character of a track that pushed machinery and drivers to their limits before safety norms reshaped the sport.