Augean stables

plural noun, Classical Mythology
1.
the stables in which King Augeas kept 3000 oxen, and which had not been cleaned for 30 years. The cleaning of these stables was accomplished by Hercules, who diverted the river Alpheus through them.
British Dictionary definitions for Augean stables

Augean stables

plural noun
1.
(Greek myth) the stables, not cleaned for 30 years, where King Augeas kept 3000 oxen. Hercules diverted the River Alpheus through them and cleaned them in a day
Augean stables in Culture
Augean stables [(aw-jee-uhn)]

Stables that figured in the Greek myth of the Labors of Hercules. The stables, which belonged to King Augeas, housed a large herd of cattle and had not been cleaned for years. Hercules was ordered to clean out these filthy stalls. He did so by diverting the course of two rivers so that they flowed through the stables.