Eton insisted that trains chuffing daily through this estate did not a ‘des res’ make, so they struck the tunnel deal with the railway company, insisting on its grand entrance too, which cleverly served to showcase the swish housing development behind it.

The stone portal was designed by a W H Budden, who worked for a period as Robert Stephenson’s personal secretary. Camden History Society’s newsletter of July 2004 suggest he may have been no more than a ‘talented amateur’, as no other structures are associated with him. Forty years later, a second portal was built alongside which closely replicated the original, including its quirky details.

Today, despite their listing as important structures in the history of urban land use, they sit overgrown and unloved, only partially visible if you crane your neck around the back of the Lume restaurant and wine bar at the end of King Henry’s Road. It’s hardly a tourist trap these days.

In the 1980s, the little arcade which includes the restaurant was in danger of toppling back onto the railway line, but has since been stabilised, further restricting the view. It’s better if you are across the other side at the little Adelaide Nature Reserve, although trees tend to block sightlines later in the year.

The residents of the Blashford tower block on Adelaide Road undoubtably have the best views of the portal, although a close ‘virtual’ second can be had if you switch Google Maps to 3D aspect and follow the tracks.