I'm hoping to be in London with a 1-6 zone Travelcard between 11:30 and 20:00. I may not be very mobile and enjoy just gazing out the window with no thought as to units, numbers or such. I'm just asking for any hints as to good lines and any quiet lines at rush hour if that is at all possible. I'm thinking Travelcard as the last trip with contactless took a bit of time and a largish telephone bill to sort out. I've already enjoyed most of the Overground, DLR and Croydon trams.