Jules de Thier, owner of the Liège newspaper La Meuse, was looking for a site to host a race, and following a meeting at the Hotel des Bruyères in Francorchamps, with burgomaster Joseph de Crawhez and racing-car driver Henri Langlois van Ophem, it was decided that the roads from Spa-Francorchamps to the former German Malmedy, to Stavelot, and back towards Francorchamps constituted an ideal triangle-shaped circuit with few tight corners and long fast sections.

At the time, the Belgians took pride in having a very fast circuit, and to improve average speeds, in 1939 the former Ancienne Douane slow uphill U-turn after the bottom of the Eau Rouge creek valley was cut short with a faster sweep straight up the hill, called the Raidillon.

The slightest error of any kind carried multiple harsh consequences, but this also worked inversely: huge advantages could be gained if a driver came out of a corner slightly faster.

At this point, many of the Formula One drivers disliked Spa (including Stewart and Jim Clark, who had some of his greatest wins there) because of the immense speeds that were constant on the track.

[10] During one of his pit stops at night, Hans-Joachim Stuck shouted to his co-driver Jochen Mass over the noise from the cars that he should "look out for body parts at the Masta Kink".

[11] After Masta, and at the end of the subsequent Hollowell Straight, there used to be a sharp hairpin at the entrance to the town itself, which was later bypassed by a quicker, banked right hand corner.

The lap record of the old triangle-shaped track is 3 minutes and 13.4 seconds, held by the French driver Henri Pescarolo, driving a Matra at the 1973 Spa 1000 km World Sportscar Championship race at an average speed of 262 km/h (163 mph), but the fastest ever recorded time of the old Spa circuit was the pole position time for the same race—3 minutes and 12.7 seconds by Jacky Ickx in a Ferrari 312PB.

In 1939, "Virage de l'Ancienne Douane" was eliminated and cut short, thus giving birth to the Eau Rouge/Raidillon uphill sweeping corner.

Since its inception, the place has been famous for its unpredictable weather, where drivers are confronted with one part of the course being clear and bright while another stretch is rainy and slippery.

Having negotiated the La Source hairpin, drivers race down a straight to the point where the track crosses the Eau Rouge stream for the first time, before being launched steeply uphill into a sweeping left-right-left series of corners with a blind summit.

The following right-hander that leads steeply uphill, which was introduced in 1939 to shortcut the original Ancienne Douane hairpin, is called Raidillon [fr].

Double F1 World Champion Fernando Alonso explained:...You come into the corner downhill, have a sudden change [of direction] at the bottom and then go very steep uphill.

Without lifting the throttle through Eau Rouge, a car would be flat out from La Source, along the Kemmel straight to Les Combes, a total distance of 2.015 km (1.252 mi).

A loss of control through this section can often lead to a very heavy shunt, as usually the rear end of the car is lost and the resulting impact is often lateral.

When fans first got to see the course configuration at the start of the weekend of the 2005 Turkish Grand Prix, they noted that an uphill kink on the back straight was very similar to Eau Rouge; the kink was therefore jokingly dubbed "Faux Rouge" (a pun on the name of the original Spa corner using the French word "faux", meaning "false").

This turn and the approach to it have been the scene of serious accidents over time, the most recent being in 2001, when Luciano Burti lost the front wing of his Prost due to a clash with Eddie Irvine's Jaguar, losing front downforce and steering, leaving the track at 298 km/h (185 mph) and piling into the tyre wall, the impact knocking him out and burying the car into a mound of tyres.

In Spa Francorchamps' tenure as a permanent racing facility, after it was removed from the public road network in 2000, there have been multiple accidents in the Eau Rouge/Raidillon combination.

In the day and age where safety is paramount to many racing organizations and governing bodies like the Fédération Internationale de l'Automobile, these crashes, of which some noteworthy ones are listed below, opened up public debate whether the Eau Rouge/Raidillon combination was deemed unsafe.

Criticism centred around the nature of the tyre barrier and run-off area of Raidillon, which tended to bounce out-of-control cars back onto the track rather than collect them.

[21] In October 2020 the circuit announced that gravel traps would be placed at La Source, Raidillon, Blanchimont, Les Combes and Stavelot.

The circuit is also shortened to 6.985 km (4.340 mi), as Jacky Ickx corner is bypassed in favour of a shorter section with more runoff for motorcycles.

[22][23] During the Formula 2 feature race in late August, a serious incident between Anthoine Hubert and Juan Manuel Correa occurred shortly after Raidillon on the Kemmel Straight.

As another Trident driver, Ralph Boschung reached the crest of Raidillon, he slowed down and moved towards the run-off area to avoid Alesi's damaged car and the field of debris.

"[35] Sacha Fenestraz, Jake Hughes, Daniel Ricciardo and Toto Wolff all agreed changes need to be made immediately to make the circuit safer.

Dilano lost control of his MP motorsport car at the exit of the Raidillon corner, hitting the barrier on the left side of the track.

Poor visibility due to heavy rain prevented the Irish racing driver from reacting in time to avoid the collision.

[48] Jarno Zaffelli [it], head of Dromo Circuit Design, the company who carried out the renovations, revealed twenty possible different iterations of Eau Rouge were evaluated, with the selected iteration chosen with the help of form of ex-Formula One drivers Thierry Boutsen and Emanuele Pirro and fine tuned with simulations for Formula One and GT cars.

[53][54] The official lap record for the current circuit layout is 1:44.701, set by Sergio Pérez in a Red Bull Racing RB20 during the 2024 Belgian Grand Prix.

As of August 2024, the fastest official race lap records of the modern Spa-Francorchamps circuit for several top series have been listed as:[55] As the long-time home of the Belgian Grand Prix and its location within the Ardennes forests it has been a popular backdrop for all kinds of fictional media, from appearances in comics and motion pictures,[163] to regular appearances in dozens of video games going back into the 1980s.

The Royal Meteorological Institute runs weather stations both in Stavelot and in Malmedy, which both show similar oceanic climates with some interior influence.