Nationwide Building Society, a branch somewhere in west London.
They didn't have any of those quick deposit slots so I had to queue for the cashier to pay my cheque in. This wasn't a problem but it was time enough for me to observe a strange man.
This man was wandering around the building, brandishing a paintbrush in a menacing way. A small artist's paintbrush (not a decorator's paintbrush), which I know it is quite hard to brandish menacingly, but he achieved it somehow. He was wandering in and out of the cubicles where people were talking to advisors, about personal and possibly delicate financial matters, but nobody stopped him. So perhaps he worked there? Yet, he didn't really have an air of authority about him - just a glazed expression and a small paintbrush.
This sort of thing doesn't happen at the NatWest.