"Sherlock" season 4 has yet to begin filming but a new report from Wales Online indicates that development for the new season is already moving forward. The report states that the new episodes will be filmed at the Pinewood Studios, which is located at the outskirts of Cardiff, South Wales, the same location used for previous seasons.

The studios may be used for most of the indoor scenes for "Sherlock" season 4 but given that the series is set in the U.K. and around London, the studios and the surrounding area may be used as a proxy location for many of the iconic places such as Sherlock (Benedict Cumberbatch) and Watson's (Martin Freeman) residence.

Not only have the studios played a major role in the filming of "Sherlock" but it has also been used for many other big budget projects, including the BBC's other hit series "Doctor Who" and last year's blockbuster hit "Star Wars: The Force Awakens."

However, the report does point out that the BBC has stated that at this point it is "too early" to confirm any filming details. Despite this response, it is important to note that Hartswood Film, the production company behind the "Sherlock" series, has an office in Cardiff and that it would only be logical for the series to filmed there.

As mentioned in a report from Cartermatt, the only instance where the Pinewood Studios and South Wales in general was not used as a primary location for filming was during the production of "The Abominable Bride" special episode. 

While a location has been set, production for "Sherlock" season 4 does not officially begin until later this spring, with a speculated January 2017 release date looming on the horizon, given that previous seasons all released around the same period.

"Sherlock" season 4 will immediately follow the cliffhanger ending seen in season 3, which saw Sherlock being recalled by the U.K. government to once again face a threat imposed by Moriarty (Andrew Scott).