The Tournament that Nobody Remembers is the name given to the Quidditch World Cup of 1877.
The tournament was scheduled to take place in the Ryn desert in Kazakhstan (QWC).
While the evidence is that something, possibly the tournament, took place, no one has any memory of playing any matches or even of being there at all. Worrying incidents such as team members showing up in another country entirely or with body parts missing, enmeshed the wizarding world in conjecture and conspiracy theories that continue to this day. The tournament was therefore “re-staged” the following year (QWC).
Lexicon timeline of Quidditch
Lexicon list of World Quidditch teams
From the Web
WizardingWorld.com (Pottermore) features:
Writing by J K Rowling on Imgur (Daily Prophet coverage of the 2014 Quidditch World Cup, originally from Pottermore):
Harry Potter Wiki: Quidditch World Cup
Tags: conspiracy theories disease illnesses and injury injuries memory memory loss mystery Quidditch history teams