So as usual I've dug one out of the archives.
This was the sunset on 9 December 2010 which I took from the passenger seat of the car travelling homeward from central London; we were on the White City flyover at the time. This chimney is on a new building on the left going westward; I've no idea what the building is for but it seems strange to put such a conspicuous chimney on an office block and I don't think it's a hospital — maybe it's something to do with the nearby BBC?
I love sunsets and sunrises. And travelling west out of London on this particular route, with its elevated sections, often gives good views of the sunset and cloudscapes.
With this shot I like the subtle pinks and greys of the sunset and the cloud patterns contrasted with the darker metallic slab of the chimney.