Cities like London are great for a short two day visit. Although it is one of the largest cities in the world, its main tourist attractions are relatively close to each other. You can see Tower Bridge, Buckingham Palace, Westminster, Big Ben and much more just walking around or with a little help of public transport. In our case it was mainly Underground. Get yourself an Oyster Card and if you stay in zones 1-3, where most of attractions are located, you will pay no more than £8.20 for unlimited rides (2019).