While called The White Lady in season 1, the high cliff ruins and scene of the crime, it is actually The Old Castle of Duino, north and west of Trieste, Italy. The scenic little coastal town and high cliff locales are not cited in the official location credits for the series, but using Google Maps, it is apparent that The Old Castle of Duino was used based on photos of it and surrounds as appeared in season 1. The main homicide investigators were sent from headquarters in Trieste to help the local cop solve the crime. The Gulf of Trieste area is gorgeous.