A new kind of specialized tourism (cf. eco-tourism, medical tourism, adventure tourism, etc.), where a traveller intentionally visits heavily touristed areas in high season, in order to observe the humorous (to the tourist of tourism at least) antics and aggravations of all the other tourists who show up at the same time for purposes of regular tourism. Also a good way to cope with your situation when this happens to you accidentally or unavoidable.
I'm not sure what to put here for Tourism of tourism. However, I took a good photo though last summer in Istanbul of two tourists taking a picture of a random cat on the street, and the cat is looking at me with this kind of expression that only a cat can make, as if to say, can you believe the things these tourists will take a picture of? So I guess it's kind of like that.