More than 2,000 cannabis plants - worth more than £600,000 on the street - were discovered in a police raid on an old Royal Mail sorting office in Herefordshire.
Police today said it was the biggest cannabis factory ever discovered in the county.
Two men have been arrested on suspicion of producing the Class B drug.
A total of 2,180 cannabis plants plus growing equipment were seized by the officers, who executed the warrant in Bromyard.
The raid was carried out after passers-by reported a strong smell of cannabis.
A safe and caring centre has been set up in Bromyard, Herefordshire, by money donated through the ITV People's Millions grant in 2005.
The HOPE Centre started life in one room in a disused building by a woman who had visions of helping young people in life. Successfully the centre now occupies purpose-built premises at the heart of its community.
The World Championship Hop Pocket Race takes place tomorrow.
Teams of four have to hurtle along with a sack weighing 70 kilograms through the streets of Bromyard in Herefordshire.