I read the Chronicles of Narnia after I’d seen the films. Right after Prince Caspian to be exact. So my introduction to this magical series started off with the scene of a train chugging along gorgeous British landscape. Remember? The very first scene, where the Pevensie children get evacuated from London to the countryside.
In terms of the music, I consider this to be the main theme of the series. When you listen to it, just notice how it transitions from being a little gloomy at first to an almost innocent sounding middle and then moving on to an epic crescendo.