Every cup of coffee needs a good drop of water and, in days gone by, this would have been the place to get it! So you're looking for a nano attached to a little bit of Maldon's history.
In 1587, Thomas Cammock put up the money to give Maldon it's first serviceable water supply. This ran from Cammock's well in Beeleigh Road, to this pump on Cromwell Hill (it was known as St. Helen's Lane, in those days).
Along with the pump (not the original, sadly), the cistern that feeds it (situated in a private garden) still survives, but is not readily accessible. The current pump was made in 1805, from cast iron, and stands in a granite enclosure.
You'll need to be very stealthy, but I hope you enjoy this historical landmark.
(This cache was published for the GeoCoffeeClub #8 event)