Cannabis farm discovered in stately home once hosting the King

North Wales Police executed a search at the historic Plas Glynllifon estate near Caernarfon, Gwynedd, under a Misuse of Drugs Act warrant. The operation took place on Tuesday, with officers planning to stay for multiple days to gather evidence. The Grade I listed manor house, famed for its 100+ rooms, had previously been home to Lord Newborough and hosted a significant event in 1969—the investiture ball for the Prince of Wales, now King Charles.

The mansion, currently under investigation, revealed a “significant grow” according to Supt Int Arwel Hughes. No arrests have been made yet, and the property’s owners remain unidentified. The site’s upper floor contained 12 rooms with mature cannabis plants, though the exact number of grows is still being assessed. Hughes emphasized the need for public caution, urging visitors to avoid the premises during the ongoing inquiry.

“There’s lots of information to process today and digital evidence we’re examining,” Hughes added. “I’m confident we’ll reach a stage where arrests can be made. Clearly, the electrics are being tampered with, and water supply is redirected inside. The property is in varying states of disrepair.”

Plas Glynllifon, which also includes an eight-mile trail network, was once marketed as a luxury hotel by a couple who acquired it in 2016. Their vision followed the collapse of a prior wedding venue venture in 2013. The building entered receivership in 2020 during a multi-million-pound renovation. It was sold that year after the hotel project failed, then re-listed in 2024 by Manchester-based developer David Savage for £2m. Reports suggest it has since been removed from the market.

The surrounding park, listed as a heritage site, continues to welcome visitors with its theme of “history, culture and nature.” Its website remains active, promoting the area as one of North Wales’s top attractions. Meanwhile, police focus shifts to uncovering the full scope of the cannabis operation and its connection to the manor’s recent financial and structural challenges.