Filming began this past week on what's generally believed to be episode three of Doctor Who Series Seven, a story by Being Human creator/writer Toby Whithouse possibly titled "The Gunslinger." This will be the first western Doctor Who story since the First Doctor tale "The Gunfighters" that aired way back in 1966.
The creative team is using the southern Spanish town of Almeria as the setting, which has also served as the filming location for several legendary westerns, including The Magnificent Seven, and the Man With No Name trilogy of Sergio Leone films starring Clint Eastwood, A Fistful of Dollars, For a Few Dollars More and The Good, The Bad and The Ugly.
According to The Daily Mail, which has posted several additional photos from the episode's filming, the Doctor Who showrunners chose to film in the Spanish town because it was more cost-effective than building a new set in the UK. The latest issue of Doctor Who Magazine confirmed that Farscape and Stargate SG-1 actor Ben Browder will be guest-starring in the episode, along with actors Adrian Scarborough, Dominic Kemp and Rob Cavazos. The episode will be directed by Saul Metzstein, who is also directing episode two. You can also find additional photos from the filming at Doctor Who TV.