Sherlock is a British television crime drama that presents a contemporary adaptation of Sir Arthur Conan Doyle's Sherlock Holmes detective stories. Created by Steven Moffat and Mark Gatiss, it stars Benedict Cumberbatch as Sherlock Holmes and Martin Freeman as Doctor John Watson. Nine episodes have been produced, the first three of which were broadcast in 2010. Series two was broadcast in 2012, and a third series was broadcast in 2014. The third series has become the UK's most watched drama series since 2001. Sherlock has been sold to over 200 territories. Sue Vertue and Elaine Cameron of Hartswood Films produced the series for the BBC and co-produced it with WGBH Boston for its Masterpiece anthology series on PBS. The series is primarily filmed in Cardiff, Wales. North Gower Street in London is used for exterior shots of Holmes and Watson's 221B Baker Street residence.