Most visited entertainment venue in London & more

I have been to concerts here in the 1970s when I lived in London, including the Last Night of the Proms in 1974, conducted by the late Sir Charles Groves. I also listened to my wife to perform there when she sang with the London Symphony Chorus. I attended a University of London Degree Ceremony when I received the Degree for my thesis from HRH Princess Royal, and more recently I've attended concerts when in London, and viewed the Royal Photographic Society Annual Exhibition in the Hall.