All Bar One is a chain of just under 50 bars in the United Kingdom, owned and operated by Mitchells and Butlers plc which was part of the Six Continents group (previously Bass) until 2003.The concept was designed by Bass as a 'female friendly' bar at a time when most pubs and bars were intimidating places for single women to go and drink or eat, hence the huge glass frontage, the open plan space and the bright airy interiors.