Shooting was taking place at St Cradocs Hospital, which was previously used in The Eleventh Hour and was Darvill's first day on Doctor Who.
Karen Gillan wrote on Twitter this morning: "Me and smith dawg. Wondering around set all nostalgic. Its a special day! @RattyBurvil get on set"
At 7.49pm, she added: "And that's a wrap! Bye bye from the ponds. We love you."
Arthur Darvill wrote: "And. . . . That's it. @KarenGillan2"
Steven Moffat and former producers Piers Wenger and Beth Willis were in attendance along with bottles of champagne.
With thanks to Doctor Who spoilers, Simon Watkins and Gareth Bundy for sharing the information on Twitter with the #dwsr hash tag.