Cops busted a £500,000 cannabis factory after they raided four bunkers dug into the ground under a farm.
Officers also seized more than 300 tonnes of illegal waste, a shotgun and six stolen cars at the site.
A llama and 22 horses, which were all kept in poor conditions, were also found at the farm.
Three men were arrested after officials swooped on the farm in the picturesque Lincolnshire village of Skendleby on September 3.
The pre-planned operation involved officers from Lincolnshire Police, the Spanish Civil Guard, the Environment Agency and Dyno-Rod.
Four bunkers made up of shipping containers were found buried 20ft underground with their entrances concealed inside the barns.
In total 12 shipping containers were used to make up the bunkers and house a large number of cannabis plants.
Officers estimate the drugs would have a street value of approximately £580,000.
Three men, aged 34, 35 and 28 were arrested on suspicion of production of a Class B drug, burglary with intent to steal, animal welfare offences and possible waste offences.
The 34-year-old was also arrested on suspicion of possession of a prohibited firearm and theft of a motor vehicle.
They have been released on bail while the investigation continues.
Detective Superintendent Rick Hatton, of Lincolnshire Police said: "We are extremely grateful to our counterparts in Spain and our partners for assisting with the exploration of this site.
"With the operation being underground we have needed some real specialist support to uncover this activity.
"Only with the skills of those who joined us from Lincolnshire Fire and Rescue, the
Environment Agency, East Lindsey District Council, RSPCA, Dyno-Rod and the Home Office's Defence Science and Technology Laboratory have we been able to get to this point."
The seven Environment Agency officers attending found approximately 300 tonnes of baled waste, 60 part-dismantled vehicles, used asbestos roofing materials, household rubbish and mixed manufactured wood, plus evidence of six separate areas used to burn waste illegally.
Environment Agency Area Director Norman Robinson said: "Waste crime is serious - it blights communities and risks real harm to people's health and the environment, and we won't hesitate to take action against those responsible.
"We've now been able to put a stop to illegal activity on this site - a testament to the determination, joint-working and intelligence-sharing between multiple organisations."
