There’s nothing that screams winter more than a cosy murder mystery - which is exactly what Agatha Christie’s Seven Dials delivers. Where was Seven Dials filmed, and can you visit the set? From Bath to Bristol, here’s everything you need to know about the Seven Dials filming locations. Where was Agatha Christie's Seven Dials filmed? West Somerset RailwayAnyone who's watched Agatha Christie's Seven Dials is familiar with those tense train shots.