scooter boy
I don't know wether you're aware of the Vanguard site but it is located on the west-side of the Isle of Dog on the north shore line of the Thames.
It's literally the nearest landing site for helicopters to the Canary Wharf complex and the financial district of the City of London. It's even closer to the square mile than Battersea Heliport.
Unfortunately, gaining permission to land at the stated site is a different story!
Captain Cop!