Info from Wikipedia
The Barbican Centre is a performing arts centre in the Barbican Estate of the City of London, England, and the largest of its kind in Europe. The centre hosts classical and contemporary music concerts, theatre performances, film screenings and art exhibitions. It also houses a library, three restaurants, and a conservatory.
The Barbican Centre is also known for its brutalist architecture.

Different performance spaces in the centre
Barbican Hall: capacity 1,943; home of the London Symphony Orchestra and the BBC Symphony Orchestra.
Barbican Theatre: capacity 1,156; designed exclusively by and for the Royal Shakespeare Company
The Pit: flexible 200-seat theatre venue
Barbican Art Gallery and the free new-commission gallery The Curve
Barbican Film: 3 cinema screens with seating capacity of 288, 156 and 156