In what month and year did Circuit de Spa-Francorchamps open?

Circuit de Spa-Francorchamps opened in August 1921.

The circuit was created from public roads linking Francorchamps, Malmedy and Stavelot in Belgium’s Ardennes. Its first planned automobile race was scheduled for August 1921, but that car event was cancelled after only one driver entered. A motorcycle race nevertheless took place on 12 August 1921, marking the circuit’s inauguration.

That cancellation is the source of a common mix-up. Some histories describe the first car race as occurring in 1922, while others use 1921 for the circuit’s opening because motorcycle racing had already begun there. The question asks when the circuit opened, rather than when its first automobile race was held, so August 1921 is the appropriate answer.

Spa later hosted the first 24 Hours of Francorchamps in 1924 and its first Belgian Grand Prix in 1925. The original track was a spectacular, roughly triangular road course and was far longer than today’s permanent Grand Prix layout.