Belgian Grand Prix - Spa-Francorchamps Circuit de Spa-Francorchamps - 44 Laps With its many varied corners, frequent overtaking, superb setting, and famous Eau Rouge bend - the ultimate test of any driver - Spa is widely considered the greatest Grand Prix circuit. At four and a third miles, it is also the longest Grand Prix circuit. Indeed, it's because of its length and complexity that this fast power circuit keeps lap times close to a long two minutes.