Pyynikin Kesateatteri is an open-air theatre operating in Tampere, Finland, known especially for its revolving auditorium. It is one of the largest summer theatres in Finland and has been running uninterrupted longer than any other open-air theatre in the country. The theatre was founded in 1948 and was originally named Tampereen Kesäteatteri (Tampere Summer Theatre). It started operating in Joselininniemi, on the shore of the lake Pyhäjärvi, where the performances continue to be held until today. In 1955 the name of the theatre was changed to Pyynikin Kesäteatteri.