How it unfolded
Snow fell over the Ardennes from the morning of 20 April 1980. Of 174 starters, dozens climbed off into team cars within the first hour as the roads turned to a mix of mud and ice. Bernard Hinault attacked with 80 km still to race. Riding almost blind through the snowfall, he covered the rest of the course alone, with barely any spectators left on the roadside. When he reached Liege, runner-up Hennie Kuiper was 9 minutes 24 seconds behind. Only 21 riders finished the 244 km race. Hinault later said he never fully regained feeling in two fingers of his right hand from the frostbite that day, and the race has carried the nickname "Neige-Bastogne-Neige" (Snow-Bastogne-Snow) ever since. He added the world road title that same year, earning the rainbow jersey.
Why it still matters
This day shows why a Monument is a different kind of honour from a Grand Tour. A three-week race is won through planning and team structure; a one-day classic is decided by a single act of will and endurance. The tradition that weather is part of the race in cycling, not a reason to stop it, is also repeatedly cited back to this race.