The Covent Garden Opera House closes for August, but there’s time to see its rich offerings of ballet and opera now. It offers Verdi:Nabucco and his rarely seen Giovanna d’Arco. Verdi is celebrated at the Theatre Collection too, with a foyer exhibition. Often overlooked, this nearby museum just off the piazza, is stuffed with all sorts of treasures. It also has performances in its own experimental theatre.