The Bells!
I recall an incident some years past, in which Mrs Marmite and I were looking round Hallgrimmskirkja (Big and very impressive church in the outskirts of Reykjavik, Iceland). We had ventured up the tower and were admiring the view from just under the bells. Our timing was a little bit off (or perfect - depends on one's point of view), as we had arrived on the floor just as time was approaching the top of the hour.
Now, Mrs Marmite is a seasoned bellringer but it still frit the shit out of her when the bloody big bell above her head gave its first godalmighty bong. A most impressive reaction ensued, in which both feet left the ground together
One got a severe arsekicking for laughing one's head off.
As a sidenote: Hallgrimmskirkja is a perfect example of how great a concrete building CAN look, as much as Coventry Cathedral isn't. The organ is pretty impressive too - looks like something off Star Wars. Must go again sometime