Someone told me about Open House London when I first got here in 2015. I tucked the note away in my memory, then every September (when it's on) passed and I missed it. I always meant to go, but either forgot, had travel planned, or was just feeling lazy. This time,though, I was determined not to miss it!

What is Open House London? Well, it's basically a weekend where you can go into buildings, ones that you can't usually access, and have a look around. I shortlisted so many buildings but it's impossible to get to more than just a handful in a day. The queues for some places were massive, snaking around corners and out of sight. I decided on one main building, the Foreign and Commonwealth Office (FCO), but downloaded the Open House app, which has a map of locations. I decided that once I'd been to the FCO, I would do a walk past some other buildings nearby and check out the queues - if they were horrendous, I would move on.

I got to the FCO right at opening time and there was a queue, but only because they weren't admitting anyone yet. I stood in line and waited. I chose this building because a) it was only ever open during Open House (some others were a bit more flexible), and b) I'd seen a few photos on the Open House website and it looked interesting. I was also mildly curious about what exactly the FCO did, but evidently they had removed all sensitive paperwork throughout the building. I'll also just say that I was not prepared for just how beautiful this building was!

We were finally admitted and I went in.

The organisation of the building was interesting. There appeared to be offices surrounding a square in the middle that was covered with a glass roof. Going upstairs, there seemed to be a lot of fancy rooms for entertaining fancy diplomats and other important people. There definitely seemed to be a clear delineation between the "work" areas and those that were used for entertaining!

I left the FCO in search of somewhere else to visit. It had been so good that it made me want to go see many more places. I passed the Banqueting House on Whitehall, but I wasn't that interested, so I went to stand in line at Admiralty House. I stood there for about 20 minutes, not moving at all. Since there were at least 40 people ahead of me, I did the maths and worked out that it would be a long time before I could go in. I think they were operating a one in, one out model, meaning I could have been there for hours. I decided to cut my losses and left.

I had a look on the app and there was a building nearby you could go to - the Supreme Court. I decided to go there, and the queue was short and moving along. The Supreme Court had been busy that week, what with a court challenge of the government for a pretty serious suspension of parliament. So it was interesting to go inside and see where all the important decisions of the land are made.

Turns out that, while it was interesting, it wasn't particularly photogenic.

I decided I'd had enough of the crowds for one day and caught the bus back home. However, on the way there, the bus went past the Alexandra Road Estate, which was part of Open House. I've always wanted to have a stickybeak in this place - it's a fascinating example of Brutalist architecture and is Grade II listed for its historical importance. It is a housing estate so you can't usually go walking in... I mean, you probably could but it wouldn't feel right. As it was, it still felt weird to be walking through there where people lived. But I'm glad I had a wander around there, as it has always interested me.

I missed out on one of the guided tours because of lunchtime which was a little disappointing, but I had a walk around on my own before walking home.