Built in 1904 as a variety theater and converted into an opera house in 1968, the London Coliseum is the city's largest theater. One of two national opera companies, the English National Opera performs a range of works here, from classics to Gilbert and Sullivan to new experimental works. All performances are in English. The Opera presents a repertory of 18 to 20 productions 5 or 6 nights a week for 11 months of the year (the theater is dark in July). The theater also hosts touring companies. Although balcony seats are cheaper, many visitors seem to prefer the upper circle or dress circle.