The BBC programme Dragon's Den is filmed in Salford after moving to MediaCityUK.
MediaCityUK is a major media and broadcasting development at Salford Quays in Greater Manchester. The BBC moved substantial operations there from 2011, and the location became associated with a range of television and radio production, including Dragon's Den.
The answer is Salford rather than Manchester because MediaCityUK is physically in the City of Salford, even though it is part of the wider Greater Manchester urban area. This geographic distinction is a common source of confusion for viewers and visitors who use “Manchester” as the broader regional reference.
The programme's filming location is separate from the locations where entrepreneurs run their businesses. Contestants travel to the studio to make their pitches, while the companies featured can be based anywhere in the United Kingdom or beyond.