I don't think they ride Eau Rouge, but Spa is sometimes used for some elite level Cyclocross: https://www.velonews.com/news/cyclocross/gallery-spa-francorchamps

I don't think they ride Eau Rouge, but Spa is sometimes used for some elite level Cyclocross: https://www.velonews.com/news/cyclocross/gallery-spa-francorchamps-superprestige-2014/ https://www.velonews.com/news/cyclocross/gallery-spa-francor... The grass bank climb is incredibly steep.