This tunnel is hidden underneath King's Cross station in London. It links a random street to the station, and is really quite hard to find. We needed the help of a local because the directions were so utterly useless. We hunted it down because it's one of the hidden points of photographic interest in London.
The tiny spec at the end is a person vanishing around the corner. I didn't wait another second for them to go because to my right, out of shot, is another person striding forth to get into shot. Careful timing.
