You'll have heard of train spotters, bird spotters, Eddie Stobart spotters. This list is quite extensive, and some will go to great lengths to "spot" their chosen object/animal/whatever to be spotted.
But.....I have never heard of this before! Yes! you read it right, a list of where to spot the Queen has been published on Yahoo.
Ah well, each to their own. I think I'll stick to butterflies.