Overview
- North Wales Police, which executed a Misuse of Drugs Act warrant on Tuesday, sealed off the vacant mansion and said officers will stay for several days.
- The cultivation covered about 12 rooms on the top floor with well‑developed plants, according to Superintendent Arwel Hughes.
- Investigators reported tampered electrical systems and diverted water supplies inside the building, which is in poor repair.
- Police have made no arrests and are trying to reach the owners as they examine extensive evidence from the site.
- Plas Glynllifon is a 19th‑century, Grade I listed house near Caernarfon that hosted the 1969 Prince of Wales investiture ball and has sat largely empty after a 2020 sale and a 2024 relisting for £2 million.