Were you to walk from the Royal Marsden’s original red-brick Victorian home in Chelsea to the hospital’s sprawling post-war campus in Sutton your arrival, some 12 miles later, would be heralded by the sudden and unexpected scent of pine trees.

The change in vegetation marks the boundary between London clay and the sandy heathland of Surrey. Belmont, a settlement of detached houses strung along roads with names like Golf Side and Sandy Lane and where the Institute of Cancer Research (ICR) is creating the world’s second-biggest cancer research hub, is truly an edgeland.

As you head south through Motspur Park, mile after suburban mile of forgettable semis gives way to stables and sewage treatment works before London gathers itself for one last spasm of urbanness at Sutton, with its concentration of high street, station and high(ish)-rise flats. Just half a mile on, at Belmont, the city loosens its grip entirely, expiring into the green belt by way of a lavender farm.

At the very spot where the capital gives up the ghost, an unreadable excrescence of buildings scars the landscape. This is the Marsden-ICR campus which stretches for 20ha between golf courses and a pair of prisons.

…