Two men have been charged with conspiracy to supply cannabis after police recovered two tonnes of the drug, valued at around £24m.
Greater Manchester Police discovered the cannabis during a raid at a property in Leigh Tenement Farm, Blackrod, Bolton, on Friday.
The seizure is thought to be one of the largest ever of its kind in the UK.
Musa Kala, 35, of Dunbar Drive, Bolton, and Raheem Latif, 27, of Leverhulme Avenue, Bolton, have been remanded in custody and are due to appear at Manchester City Magistrates' Court on Monday.
Detective Superintendent Joe Harrop said: "Our officers uncovered a large-scale and sophisticated illegal operation at the location, housing a significant volume of illegal drugs.
"This seizure marks a major success for our officers - it removes a major source of harm, disrupts criminal networks and helps make neighbourhoods safer."