The walk-ability of London. This is true especially in the central, or closer to central, areas. I love that you can start in one area and easily see so many other things just by walking around. There are so many things within walking distance of my apartment (or flat) – and that includes the grocery store and the tube station which can take me to so many places. A bit of a longer walk (but still less than 20 minutes) takes me to one of the nicest parks around.