a very dirty or cluttered place – Augean stables, gigantic (hopeless, dire) mess. [From the name of Augeas, legendary king of Elis, whose stables (which sheltered 3000 oxen) had not been cleaned for thirty years. Cleaning the Augean stables was one of the twelve labors of Hercules.]
Example: У тебя не комната, а просто авгиевы конюшни! Когда ты в последний раз здесь убирал? - Your room is a real pigsty! When was the last time you cleaned it?