Pocket Watch Symbolism

What is the symbolism of the pocket watch in Pan's Labyrinth?

I just got this movie (my favorite!) And it seemed that the pocket watch was captain of the symbolism. I know that his father gave him so when he died, he could not break a rock to tell to his son when he died (or something very similar, it has been a while), but there other symbols of it? And what other symbolisms in the movie that you liked?

The pocket watch is a bomb, you will find at the end.

The Doctors Pocket Watch