Spa-Franchorchamps
The Circuit de Spa-Francorchamps, in short Spa, is located in the southeast of Belgium, in the Belgium’s Ardennes region.
It is one of the old-school historic Formula 1 tracks, and after Monza, Monaco and Silverstone it is the fourth most raced F1 track. Besides the F1, Spa also hosts several other international events like the 24 Hours of Spa (as part of the IGTC), the World Endurance Championship (WEC) 6 Hours of Spa-Francorchamps, the 4h of Spa of the ELMS, and the TCR Spa 500.
To give an idea about the historic importance of the track, here is a list of winning drivers at Spa: Michael Schumacher; Pedro Rodriguez; Jimmy Clark; Jo Siffert; Jacky Ickx; Henri Pescarolo; Juan Manuel Fangio; Ayrton Senna; Dan Gurney; Alberto Ascari etc.
The original track was designed in 1920 and has seen many changes since then. The biggest change was done in the 1979 when the track was modified and shortened from a 14.10 km (8.76 mi) circuit using public roads to a 6.95 km (4.32 mi) permanent circuit. The main reason to make those changes was that the old circuit was deemed too unsafe (read: too fast).
The current circuit retains much of the flavor of the original course including many of its signature turns like La Source, Blanchimont and the daunting Eau Rouge-Raidillon combination. The “new” Spa features a demanding, purpose-built section that sweeps down a valley through the fast Pouhon curve and the Campus esse bend before rejoining the “old” circuit near Blanchimont.
The result is among the most challenging circuits on the current Formula One and sports car racing schedule. And then we didn't even start talking about the notoriously unpredictable weather.
Some extra resources for a deep dive: