Today for work I was in a Boots manufacturing building and the Boots engineer who was showing me around was feeling very talkative and gave me a fascinating history of the building in the photo below.
Building D10 on the Nottingham Boots estate is a grade 1 listed building which is probably the highest rating for a actual fully functioning factory, the picture below shows one half of the central section, the rest was behind me when taking the photo, built out of concrete in 1933 the architect won international awards for his design.
The roof which you can see in the photo (click photo for larger image) has 56,000 dinner plate size glass discs, 50mm thick each hand made and cast directly into the concrete and even today they can't work out how they did it without them cracking or shrinking loose, no silicon seals, no rubber gasket's just a case of casting the concrete around them.
I took this photo because the sun was shining through the roof and it just looked pretty.
The same architect built the building next door Boots building D6 a grade II listed building which is some form of unique cantilever design, apparently a Spanish architect believed it would collapse and phones up every year to see if its still standing.