In 1961, the year I was born, the Berlin Wall went up, and Yuri Gagarin became the first man in space on his street.

Closer to home, in Walworth, south-east London, an 80ft-wide silver cube appeared on the roundabout at the Elephant & Castle interchange. It is made up of 728 stainless-steel panels, and rises 20ft above pavement level.

The natives never knew why it was there, merely what it symbolised: an eyesore on a patch of land destined to be lumbered with more doomed monoliths than any postcode in London.

To its architect, Rodney Gordon, it was a clue to  the urban future we might inherit, the more modern and moonstruck we became.

For me, it became a Checkpoint Charlie beyond which the West End beckoned via the roads stretching from the Elephant & Castle to London’s main bridges and, in the words of my nearest and dearest, ‘over the water’.

From Michael Collins’ The Elephant’s Graveyard, The Observer (2001)