Sometimes it's hard to keep a strong story through so long. It usually become boring and always the same, but in this story you'll be always surprised. In the beginning it's very clear that the story is full of secrets, lies, etc. That will be the key for the story to have always something different to develop. The dark past will also be one of the most important thing in the story, because it will always return to try to explain why the things are like that in the present.
The actors will be other of the most important things, because their performance will gave credibility to the story, and will be an extraordinary complement for it. For the other hand, I have to highlight the production, that will gave to the story the awesome scenery, and also for the cameramen who did an awesome job with the shots. The soundtrack, which was created exclusively for the soap opera, as good as the film ones.
In summary, as much the story, like the actor and also the production were essential to make this strong soap opera, which will keep you always expecting what will happen, and surprising you about the dark past of many characters. You won't imagine how will everything end. Definitely, a masterpiece.