The organiser of our trip had arranged for the Church of England building to be open for two hours in the morning. I bumped into her at the coffee shop and we agreed to walk down there together. We boldly entered the church and started taking photographs. A voice was heard "may I ask what you are doing" and my co-photographer explained that there was permission. "Well no one told me, said he, and we are about to start a service". So we quietly stayed a minute or two longer and then moved on.
I got an email the following day to say no wonder he was a bit abrupt. We were in the wrong church.