I'm beaten by this one, despite having looked at the TfL website, which I found quite poor. Though maybe it's me being dim. My aunt and uncle are heading off to London for the weekend shortly. They each have a Senior Railcard. They also have PAYG Oyster cards from a previous visit, and they are intending to go to Hampton Court on the Sunday that they are there. They asked me if it would be cheaper to use their Oyster cards, or whether they should get a one day Travelcard if they can get a discount on the fare with their Senior Railcards. I've looked but I find the London fares a bit mystifying, especially since the changes in January this year. Please could a London expert give me a bit of guidance, and point me in the right direction as regards where the information can be found on the website? My uncle is a bit fussy and likes to know where information comes from in case he runs into any problems. Naturally, I won't take all the credit myself for giving him the answers! Thanks in advance.