I’ve already told you in my list of tipps how to save money while traveling to always look for free things to do. And I’ve found a free walking tour in London, which is just a bit different than the normal walking tours you would find.
Note: It still works on a pay as much as you like basis. And I’m pretty positive that after the tour you will feel like you want to at least donate a little bit of money because, to be fair, your tourguide spends 1.5 hours of his day telling you things that he has told so many times before. At least I wanted to.