The Tate Modern is one of our favourite museums in London, you can check out some awesome modern and contemporary art for free. They've got paintings, sculptures and installations from artists like Picasso and Kusama. Plus, there are always cool and quirky exhibitions and events happening, so it's worth a visit if you're into art or just looking for something fun to do in the city. It also has a free viewing platform at the top of the building, with great views over London, along with a cafe!