The ADAC Ravenol 24h Nürburgring — commonly called the Nürburgring 24 Hours — is one of the world's great endurance races: a round-the-clock contest held every year in late May or early June at Germany's Nürburgring, organised by the ADAC with Ravenol as title sponsor.
What sets it apart is the circuit. Each lap combines the modern Grand Prix circuit with the legendary Nordschleife ("North Loop") — more than 25 kilometres of narrow, undulating track through the Eifel forest, long regarded as one of the most demanding stretches of racing road anywhere.
Like other enduros, each car is shared by a crew of drivers who swap in stints through the day and night. The grid is huge and mixed: top-class GT3 cars fight for the overall win alongside touring cars, cup machinery and amateur-friendly classes, with a typical entry of more than 130 cars and around 700 drivers. Winners have included the factory programmes of Audi, Mercedes-AMG, BMW, Porsche, Ferrari and Lamborghini, often after 24 hours of weather and traffic chaos decided by the smallest of margins.
For the sport's other round-the-clock classic, see What is the 24 Hours of Le Mans?.