During the years 1831 and 1860 London suffered many cholera outbreaks with tens of thousands of people dying from the disease. It was Dr John Snow who made the connection between the polluted drinking water and the epidemic. During one outbreak in 1854 Snow realised the victims all had one thing in common - they had all used water pump in Broad Street. He had the handle to the water pump removed and within no time the spread of the disease halted.
The original site of the water pump is just outside the pub bearing his name John Snow but a few yards away is a replica with this plaque underneath: