 Filming began on February 12 , 2007 in Auckland . The scene where the Pevensies return to the ruined Cair Paravel was shot at Cathedral Cove . The filmmakers chose the location because it had a tunnel @-@ like arch , which echoed the train tunnel the children go into before being summoned back into Narnia . Henderson Valley Studios was used for the Pevensies ' ancient treasure room and the Underground station . 
