To Charing Cross, where my friend and I are due to meet for a tour of the Tube station’s disused tunnels with Hidden London. Not wanting to be late, I arrive 45 minutes early and pass the time in the Waterstones at Trafalgar Square. The air outside is cold; I can see my breath.

I took my first Hidden London tour in October 2016: the lost tunnels of London Euston. My girlfriend and I took in the station’s historical information imparted by the brilliant guides, the vintage advertising posters and, of course, the marvellous tunnels and ventilation shafts.

I was hooked. I’ve since toured Aldwych and Down Street, with a ride on the Mail Rail at the Postal Museum thrown in for some variety, and now Charing Cross.

When I get weary of the noise, the order and the restrictions placed on the surface of the city, I long to return to these tunnels.