As mentioned yesterday, I found myself on a rather special double-decker bus on a trip to a mystery location, described as an overlooked piece of post-war architecture.

The location, suitably enough for a trip on a bus, was a bus garage – but not just any bus garage. This was a trip to, and inside Stockwell bus garage – which contains what was at the time of construction – Europe’s largest unsupported roof span.

Our trip in the 60-year old bus took us down the same side street used by modern buses, and into the courtyard outside the bus station for a look at the ribbed concrete roof. One of the volunteers on the bus gave a brief talk about the bus, and the bus station, but admitted his knowledge was more bus than building oriented.

However, we then drove inside the bus garage, which took our guide slightly by surprise and he noted that he had himself never been inside, so treats all round this time.

Inside, stop for a bit, a loop around the station and then back out to return back to the South Bank.

No chance to get off – I suspect that would have strained the permission to dart in and out again – and all the photos were taken through the windows. Photos incidentally, that I wasn’t expecting to take, so I only had a cameraphone instead of my usual big camera on me. Sorry!

The bus we were in was built in 1950, and so is older than the bus garage, which was built in 1952, during the post-war shortage of steel. Hence, the architects, Adie, Button and Partners, with the engineer A E Beer, chose to build the roof out of concrete instead of the usual steel supports.

The 120 metre long roof structure is supported by ten very shallow “two-hinged” arched ribs which make up the distinctive shape of the structure.

Since 1988 the garage has been a Grade II* listed building reflecting its importance in post-war architectural and engineering history. Google satellite view.

As a building, I like it a lot, and it has somehow escaped the worst ravages of time that afflicted concrete housing of the same era, probably in part due to not having residents despoiling the structure. I am not alone in liking it, as self-described flâneur, Will Self has been on a mission to educate people about this architectural gem hidden from casual observers behind a residential street.

I also liked not just the architecture, but also how the shiny red buses, all out of service were lined up in marked contrast to the grey concrete ceiling arching down over their heads.

I’ve long planned to take photos of it if and when I am in the area – never expected to be able to go inside though!