I never thought about the words ‘big smoke’ till I read about George Orwell’s London. I go there sometimes, and get black snot sneezes on the underground.

I was there on Saturday for Peter Carty’s travel writing workshop. Every minute was carefully planned to propel us into the craft. Our lunch time challenge was to write about Fitzrovia, so croissant in hand, I tackled telecom tower.

The big man at reception burst into a belly laugh when I asked him what happened inside. “Well I think, you know, they probably just do BT things!” I wondered if I could go up, but he said it was just for staff.

It was built in the ’60’s from glass like old pebbles and I couldn’t look at it without imagining a Russian spy scaling the walls – there’s something communist about the aerials.

No-one much else seemed to know about it either. The man in Halifax wasn’t sure what it was for but helpfully pointed it out from the pavement. The students didn’t know and hadn’t wondered.

But two BT staff were having a smoke on the corner. They’d been up so often setting up conferences they’d forgotten they used to be impressed by it too. “The best thing about it” says the younger one “is that it’s not like the other ones, the shard ‘n that, it’s the only big one round here. On a really clear day you can see the Dartmouth crossing from up there.” I like to think about that.