The Bank of England is normally open on only one Saturday per year - on Open House Weekend, and the queue to get in has always been awful. However, as part of the London Festival of Architecture - they will be open for a second Saturday so there could actually be a chance to get in without having to spend hours outside in the queues.

If interested - you want to be there on Saturday 28th June and the tours start at 10am. They take you round the impressive interior and the museum is also open. The museum is somewhere I have wanted to visit for ages, but like the bank - is only open Mon-Fri, so this is a double treat.

http://www.colf.org/event-details.cfm?e=613