Sadler's Wells Theatre is a performing arts theatre in London. It is in Rosebery Avenue, Clerkenwell in the London Borough of Islington. The theatre which now stands is the sixth building that has been there since 1683. There are two performance spaces: a 1,500 seat main auditorium and the Lilian Baylis Studio. There are many rehearsal rooms and technical facilities. Sadler's Wells is one of the most important theatres for dance in the United Kingdom. Several dance companies perform there.