London's Best-Kept Secrets: East Finchley Sulphuric Acid Reservoir

The supply of laboratory-grade sulphuric acid for the nation's school science lessons has to be kept somewhere, and that somewhere is this reservoir in East Finchley. The previous storage facility, a hospital swimming pool, proved unsafe and so in 1998 the Government decided that Finchley's artificial lead-lined lake, unused since the war, was the perfect successor.

Controversial at first, the half-mile wide expanse of H2SO4, surrounded by acres of blighted wasteland, has become a popular destination for a relaxing day out - a place where all the family can don breathing apparatus and watch the ducks dissolve. It's also handy for murderers, or anyone with evidence to destroy.