The reservoir in Islington’s Claremont Square has railings round three sides, but a brick wall on the fourth.
Back in the 1820s the New River Company decided to encircle the then uncovered pond with a fence for safety reasons. When the job was finished, they passed the bill on to the residents of the square. Those living on the north side claimed that they lived in Pentonville Road and not the sqaure. Therefore they would not be contributing, as their road had been up and running as London’s first M25 for about 70 years.
The New River Company got them back though, by replacing the fence with a stark and grim brick wall which remains to this day.