Can you get to Cardiff from London by Tube?

No, you cannot get to Cardiff from London by Tube. The Tube (also called the Underground) is a public rapid transit system in London. It does not serve any destinations outside of the Greater London area. To travel from London to Cardiff, you can take a train from Paddington Station to Cardiff Central Station. The journey time is approximately 2 hours. Alternatively, you can take a bus from London Victoria Coach Station to Cardiff Central Bus Station. The journey time is approximately 3.5 hours.