30 St Mary Axe, officially The Swiss Re Building, colloquially The Gherkin is one of the most prominent and tallest buildings in modern London, but it's proving difficult to find out for sure whether it has any public viewing platform or bar or restaurant accessible to the public, or any open days or such when an exception might be made to allow public viewing at certain special times.
There is a private restaurant and bar but not just anyone can go there.
Is there any way for a normal member of the public to view London from this building?