Doctor Who Confidential (2005) : 5x6

The cast and crew get a trip abroad. But not to Venice, because as episode writer Toby Whithouse explains, modern day Venice doesn't really look like 16th century Venice anymore. Instead the episode is shot in Trogir, a small medieval town in Croatia that is the spitting image of 16th century Venice. However, Matt Smith and Toby Whithouse do take a trip to Venice and meet up with Francesco Da Mosto, who takes them on his boat and gives them a unique tour to illustrate how the world's most beautiful city works as a back drop to Toby's fiction. Narrated by Alex Price and featuring interviews with Matt Smith, Karen Gillan and Francesco Da Mosto.