3 Mills Studios is London's largest studio complex, set on a 20-acre island site and surrounded by a tidal river and canal. Originally housing three mills dating back to the 1500s, the site was used for bottling and warehouses throughout the 1900s until it became a film and television studio in the 1990s. The site offers extensive location opportunities including exterior streets, bridges, exterior warehouses, office blocks, houses, external black iron staircase, basements, Grade II listed buildings (Regency style dating back to 1817), cobbled streets, corridors, boardroom, car parks, walkways etc. The studios interiors and exteriors have often doubled as police stations, hospitals, nightclubs, airport lounges and even New York and Victorian streetscapes. There are nine filming stages and two theatrical rehearsal stages ranging from 3,200 sq. ft. to 13,500 sq. ft. As well as the studio spaces, there are rehearsal rooms, props stores, workshops, dressing rooms, make-up rooms, green rooms, a screening room, warehouse space (available for commercial storage purposes only), catering, a restaurant / bar, parking and 24-hour security.