It would be a rather difficult journey by train, the plane takes an hour and a half and would cost from about £50 return.
How many days would it take? Madrid is a vibrant historic city with some of the best museums in the world. I would allow three full days to get to know it a bit.
Sadly, I agree that flying is probably most efficient. The train is just a bit too complicated. This means that it will take you 5/6 hours from Central London to Madrid airport - and Madrid is one hour ahead of London.
Madrid is a big city with much to see. You would need at least 4 days to make a dent. It is worth it, especially if you have any interest in art. You can buy a ticket that gets you into 3 major art museums(Prado, Reina Sofia and Thyssen-Bornemisza), each one untique and important.
-:- Message from TripAdvisor staff -:-
This topic has been closed to new posts due to inactivity. We hope you'll join the conversation by posting to an open topic or starting a new one.
To review the TripAdvisor Forums Posting Guidelines, please follow this link: http://www.tripadvisor.com/pages/forums_posting_guidelines.html
We remove posts that do not follow our posting guidelines, and we reserve the right to remove any post for any reason.