Penrhyn appears to be unremarkable and indistinguishable from any of its three neighbours. But from October 1976 it was the subject of an intense under-cover police surveillance operation and on 26 March 1977 Number 23 Seymour Road Hampton Wick hit the headlines around the world in the biggest possible way.

Operation Julie was a UK police investigation into the production of illicit LSD by two drug rings during the mid-1970’s. The operation, involving 11 police forces over a two-and-a-half year period, led to the break-up of one of the largest LSD manufacturing operations in the world. One of the drug factories was in the attic of 23 Seymour Road. Further information can be found through the links below which include a background article from BBC News Magazine, a review of a recently-published autobiography by one of the drug gang and a set of three YouTube videos which cover the full 30-minute documentary on Operation Julie made by the BBC Wales in 2006.