The library is located in the district of Arganzuela, a gentrifying working class neighborhood along the shores of Madrid Río. Madrid Río is a pleasant park which runs the length of the Manzanares River and was inaugurated in 2011, not yet giving time for the neighborhood to catch up in terms of venues and restaurants, though it should be getting better.
I am currently sitting un an unremarkable, firm office chair in the study area, next to a large window which unfortunately provides the grandoise view of gray slab of concrete. The study area is located in a basement, and though it receives a certain degree of natural lighting, it would be dark if they turned the lights off. The workplace is not all that unpleasant. People are focused, and the crowd is composed mostly of university students and a couple of older adults.
The tables are large, and each one has six chairs, though whoever thought about this layout knows little about personal space or the spreading habits of Spanish students. The place must be at around 70% capacity on a Wednesday at 1:30pm, though people are leaving for lunch. The best time to get a good spot at a library in Madrid is always from 9:00 to 10:00 (early) and 14:00 to 16:00 (lunchtime). Some of the bookshelves are sparsely populated, which brings the same sensation of scarcity that a half-filled grocery store would bring. Fully packed shelves are signs of a healthy library.
The walls are painted light gray, and the columns are Mexican pink, not good color choices in my opinion. But it's not an unpleasant place to be. The floor is polished concrete, quite shiny. One could call this place half brutalist and half government office. There is a quiet hum from the air conditioner, which can be perfectly ignored. Perhaps a good thing of having the windows high up is that it offers little opportunity for distraction, though I'm the kind of person that welcomes distraction now and then.
The bathrooms are quite good, each stall has a solid metal door, and true brick walls covered in mosaic from floor to ceiling, with independent light. There is a sordid sense of privacy, and asking forgiveness for my candor, I would suggest to pick a good book before bunking in one of these stalls.