London is a really amazing city, with so many things to do and see, and all free or very cheap. There is no need to just go to all the tourist landmarks, there are many others. Here is my list.
"Brick Lane hosts one of the largest street foodmarket I have ever seen. There are high quality street food from around the world. I can't decide which food is best so I leave that up to you."
"It is Free entry. The building is beautiful and was a former home. It has incredible paintings by artists such as Titian, Rembrandt, Hals (The Laughing Cavalier) and Velazquez."