From the Wikipedia page [1] The South East London Green Chain, also known as the Green Chain Walk is a linked system of open spaces between the River Thames and Crystal Palace Park in London. In 1977 four London Boroughs and the Greater London Council created this Green Chain of 300 open spaces to protect them from building activity. The four London boroughs are Bexley, Bromley, Lewisham and Greenwich. Many parts of the system are also part of the Capital Ring route. The website is [2]