This is about Lucia, a young woman much in the tradition of James Bond. Her hidden talents reveal themselves over the course of the series. The story involves several interrelated characters, but not too many to keep track of. I learned a lot (starting with little knowledge) about life in Spain up to World War II and into it. The title refers to an English neighborhood near a large mine, that was controlled by England at the outset.
Each episode leaves something hanging, which forces you to watch the next. Fortunately, the next was just as good as the last. The acting and casting were great.
I was first captured by the beauty of everything, especially the old Spanish buildings (including houses). It made me want to go there.
The music was excellent, if you listened to it. It was not intrusive, so you need to remember to listen.
Technical note: The version we saw had "closed captions" in both English and Spanish, and real subtitles in English, but they overlapped, which meant I had to turn off the cc. Occasionally the English parts were hard to understand, but there were not many and none seemed crucial.