Complex sentence: Filming for the episode's outdoor scenes began in the afternoon of 11 March 2008, with filming of the cold open taking place on West Mound Cresent in Tonteg.
Split into simpler sentences: Filming for the episode's outdoor scenes began in the afternoon of 11 March 2008. The first outdoor scene filmed was the cold open, on West Mound Cresent in Tonteg.