My abiding memory was not of the Wall, but of the U-bahn from the West whizzing non-stop through stations in the East, their colours and adverts frozen in time from before the Wall. On each platform a couple of soldiers who had drawn the short straw of long hours guarding an underground border, and each other.

I can only remember Checkpoint Charlie on Friedrichstrasse spatially. A sense of having to look towards the guard post and the Wall around a corner for a view towards an end of things, a shutting down, the impossibility of just wandering back over a border I’d crossed from Moscow the day before.

Checkpoint Charlie has become s a photobooth. Tourists pose with costume guards, who one moment adopt the erect salute of the military characters they are dressed as, the next lean back into thumbs-up selfie gurns. Where once there was a border, barriers, a no man’s land, there is now a flowing street of the usual western shops, traffic and of cyclists dodging the tourists made road-blind by their cameraphones. Friedrichstrasse is free flowing.

Wilhelmstrasse is where the blockade is now. All the security apparatus seems to have moved to guard that monument to freedom and democracy, the new British Embassy. Wilhelmstrasse is truncated by smart bollards glinting like modernist Daleks and cut off except to all but policemen and bikes.

Michael Wilford’s embassy building is a complex mix of wall, fortress, defence, security, but with a cheeky bit of post modernism peeping through, that says We are alright really, we don’t take ourselves too seriously, we’re rather fun. Don’t worry about the drawbridge, the uniforms. But the library, cafe and restaurant once open to forge good relations with the locals are no longer freely accessible.

By the bollards at this end of the street, there is a new rectangular box, a new glassed checkpoint, guarding against the perceived threats from the outside and from within. A little bit of Berlin frozen from the time of the Wall.

As a footnote: this grand building is not the property of the crown, nor of the nation of homeownership. It was built and is maintained on the never never of PFI, originally by Bilfinger Berger who then sold their interest to a private company whose name seems to perfectly encapsulate post industrial UK PLC and hangs without an article: Secondary Market Infrastructure Fund.