Interlagos, Sao Paulo, Brazil. The scene of so many classic racing encounters, and for me an almost mystical place – a legendary venue the other side of the world from me that I never expected to have the chance to see, but was lucky enough to visit a year ago for the penultimate round of the FIA GT1 World Championship. With the Brazilian Formula 1 Grand Prix taking place at the track this weekend, it seems a good excuse for me to look back on my trip to Brazil and take a closer look at the track itself.

The track is the spiritual home to Brazil's Formula One elite, worshipped by Felipe Massa (he talks of delivering pizzas to the track as boy), eulogised by Rubens Barrichello (looking over the wall from kart track, dreaming of one day racing on Interlagos' hallowed tarmac) and enshrined to Brazil's deified racing son, Ayrton Senna. But its history goes much further back.

Officially called the Autódromo José Carlos Pace, Interlagos is a track of two halves and two histories: the current 2.7 mile perimeter blast and interior twists (outlined in red) balanced against the visible, enclosing embrace of the legendary original 5-mile circuit (yellow).

Evidence of the old track is all around (and sometimes beneath you), just like the legendary banking section at Monza in Italy – though it's something that the low-down camera angles of most F1 races rarely show you, that you only catch glimpses of. In real life, as at Monza, it's the new track that quite obviously sits in the shadow of the old – but to the detriment of neither.

Interlagos now sits in a surprisingly green oasis surrounded by the ever-expanding urban sprawl of the enormous city of Sao Paulo, but originally the track was out in the countryside on the outskirts of the town. The land was bought by property developers in the late 1920s: a British entrepreneur, Louis Romero Sanson, teamed up with a French architect to plan an enormous suburban development including a sports complex and race track. 

The project was based on the Swiss resort of Interlaken ('Between the lakes', hence Interlagos in Portuguese), as the chosen site sat between two artificial reservoirs – but the world economic crisis of the late '20s killed the project in the short-term. However, road racing had already got a hold on Brazil, with scratch street races being the primary showcase for the new sport, as in Europe. Sao Paolo held a Grand Prix on its streets in '36: but a French driver crashed – killings herself and four spectators, with another 37 injured. The glorious but lethal road racing era was nearing its end: a permanent track was needed and the Interlagos plan was back on the agenda.

The continuing lack of funds meant that the track project was scaled back: the grandstands and facilities would have to wait for many years. But the important bit, the track, was laid down in 39 and hosted its first race in May 1940. Interlagos' first international race was held in 1947 for GP cars, and the track quickly gained a reputation as a challenging and exciting track for drivers (Check this for a look at the early era).

Sanson's company continued to manage the circuit until 1954, when it was sold to the city for a nominal sum, and in 1957 the track was divided to present two options: the high-speed 3.2km banked outer ring, and then the more technical inner section, creating a very unusual layout full of flat-out straights, banking, parabolic curves and switchbacks (see this video from a 3-hour sportscar race in 1964 to see how basic the facilities were in those days).

Interlagos was closed for three years in 67 to bring it up to international F1 standard, and after further improvements the track was certified as ready in 71. It quickly proved a happy hunting ground for local drivers: the first race for F1 cars in '72, a non-championship race, was won by Argentinian driver Carlos Reutemann. The first full World Championship round was in '73, and was won by the 1972 F1 champion (and Sao Paulo local) Emerson Fittipaldi (check out this video for F1 footage, and then this one for Emmo taking a saloon round the track – featuring a great intro and great facial hair). Emmo won again in '74, with fellow Brazilian Carlos Pace taking the victory in '75 (here's some good quality footage from that year).

The last race held on the original 5-miler was in 1980 – and that was almost cancelled because of safety concerns from the drivers. The track's many low barriers, ditches and water hazards made it more assault course than F1 track… F1 switched to the Jacarepagua track in wealthy Rio De Janeiro in 1978 before returning to Interlagos for its final swan song years in 1979 and 1980. The money wasn't there to upgrade the track and Sao Paulo's GP days were over for the time being.

On my visit to the track I was able to make the pilgrimage to the old asphalt, which is still remarkably intact unlike so many other refurbished places, and is also more than obvious: there's no hunting through the undergrowth to find this behemoth. Instead of diving down to the left, the original Interlagos track carried on with a flat-out trajectory through a swooping left-hander. 

This featured substantial banking, that if not on the levels of a Daytona or Brooklands certainly meant that most cars could keep the pedal fully flat to the floor. 

Some locals were kind enough to demonstrate the principle… Here you can also see the Senna S in the background, which gives you an idea of the gradient change of that new section.

Exit the corner and keep the foot buried down the Retao back straight on the run down to Curva 3. 

Curva 3 featured more gentle banking, though contemporary cars then had the challenge of breaking for the following tighter left that led them into the long complex of repeating inner loops.

The option was to go straight on if you were only tackling the outer perimeter track: the left in the distance at Juncao signalled the start of the long drag back up the hill to the pits.

But continuing on the regular line, a rising straight with a right-left kink led into the original Ferradura hairpin, most of which is now under the modern green run-off. 

This is where things get interesting. The cars now ran against the current direction of traffic, back up this short straight and towards what is now the Subida Do Lago sequence.   

Now this corner is a challenging double-apex downhill left; originally the track described a parabolic uphill right, with the original radius following the small track you can see on the right here.

Still going against the current track direction, the cars made their way back up the Reta Oposta towards the arcing Curva Do Sol corner. 

What is now the reduced Curva Do Sol third corner leading onto the Reta Oposta was originally another, even bigger parabola coming in the other direction. This wide-angle gives a good impression of the first half of it, which would carried on curving around. 

Next up another short squirt down a straight to the Sargento corner. Here I'd been picked up by a guy who claimed to be security guard and I thought I was about to be murdered. Luckily for me I wasn't, and it gave me a good and unexpected opportunity to ride down some of the old and new sections of track before ducking back out onto the circuit again.

Exiting Sargento, once again you went back on yourself and up to the Laranja curve, on the outside of Ferradura. Four bits of track run parallel here! All the Sargento section (to the right here), which originally ran round a small reservoir, was filled in during the '90s renovations.

For the next couple of corners nothing has intrinsically changed for 70 years. Pinheirinho and Bico De Pato are still as challenging as they ever were: there's just better tarmac and safer barriers.

The banzai swoop through Mergulho, marked by the modern blue run-off, leads to one of the most important corners on the track.

Juncao: Junction corner, which linked the outer 'oval' and main track marked the acceleration point for the return to the start.

These kerb stones have been run over by some of the most legendary drivers on the planet. Thankfully, they're still here to be seen and touched. 

The uphill run has to be experienced to be believed. TV commentators always talk about this corner being so important, but when you see how steep it is you realise just how vital a good exit is. The original Juncao was at the bottom of this straight, and predictably was another parabolic corner: the new cut-off Juncao from the '90s is on the right in this shot.

From then on, you just accelerate and pray. I spoke to '70s and '80s Formula 1 driver John Watson at Interlagos, and he talked about the track in hushed tones, perhaps mostly because it was a miracle that no F1 driver was killed here in the fragile cars of the day. He talked of how you nailed the throttle at Juncao – and held it down for about 20 seconds. Through the three apexes of the sinuous twists of the start 'straight – which looks more like the result of an earthquake than a deliberate idea – through the banked first corner and all the way down to Curva 3, three quarters of the way round the perimeter and almost back where you started. Would your brakes work? If they didn't, you were in real trouble. F1 drivers were real men in the old days… 

In 1985 the circuit was renamed from Autódromo Interlagos to Autódromo José Carlos Pace following the death of the legendary Brazilian F1 driver in a plane crash. Local races continued until 1989, with the classic Mil Mihas (1000 Mile) races, lower formulas and GTs still thrashing round this amazing place. 

In 1989 Rio in turn lost the GP due to their own financial trouble – an ironic twist on Interlagos losing the GP a decade earlier. But this time Sao Paulo was ready: it was time for change. The new Interlagos was born and the second great phase of the Autódromo began.

Jonathan Moore