In the US, we go on vacation. In Europe, they go "on holiday". We've just returned from a "holiday" in London.
London proper, is home to 7 million people, with 5 million more in the greater London area. It's an amazingly busy, vibrant city, with huge crowds everywhere. For this small-town girl, it was quite an experience. I'll try to remember that I'm back in the south and shoving past people is frowned upon.