On the way to Valley of the Fallen, I visited the royal palace of El Escorial, which was the headquarters of the counter-reformation (and the Spanish Inquisition). There is really not much to see, but it is noteworthy for the violent history just mentioned.
Valley of the Fallen is a very strange place indeed. While the site is quite an impressive engineering and architecture project (the cross is 500 feet tall), it does not seem to know what it is dedicated to. Is it the tomb of Dictator Francisco Franco or a memorial to all the victims of the Spanish Civil War? It seems that it cannot be both. As such the monument remains a subject of intense controversy. This is reflected in the difficulty of getting there, which for me involved an expensive taxi ride from Escorial.