I would like to travel from Porto to Seville, Spain by train or bus. Can it be done, which is better and any details would be appreciated?
You can take a train from Porto to Lisbon (hourly departures, 2.5-3 hours), then a quick taxi in the city, then a direct bus from Sete Rios bus station to Seville (3-4x/day, 7 hours, www.alsa.es).
Alsa also has a bus from Porto to Madrid (7.5 hours, maybe only 1x/day), then you can catch a fast train from Madrid to Seville (2.5 hours).
To compare budget flights, see www.skyscanner.com.
Thank you.