Spanish trains are said to be the most inexpensive in Europe. All major cities in Spain are very well connected by trains.The National Railways in Spain is called RENFE (Red Nacional de los Ferrocarriles Españoles), so it's not surprising they use the initials. Most railways are operated by RENFE, however there are some narrow-gauge lines are operated by FEVE (Ferrocarriles de Via Estrecha) and a few other carriers in individual autonomous communities.
For long journeys, the TALGO (Tren Articulado Ligero Goicoechea Oriol) is a good option. Fast, comfortable and efficient. TALGO and Inter-city trains have buffet and bar services onboard. Train tickets can be purchased in advance from main stations, ticket agents, on-line and from authorised travel agents
Besides the regular trains and sleeper cars, RENFE has inaugurated the AVE (Alta Velocidad Española), a high speed train network linking many of the major cities. Spain can boasts of more high speed trains than any other country (perhaps with the exception of Japan). Until recently, most AVE routes ran from Madrid to the other important cities, but now there are cross-country lines, and Malaga to Barcelona is an example. These trains travel at around 300 kilometres an hour (approximately 200 miles) and considerably reduce journey times.
RENFF also runs a series of special trains. The most outstanding is the "Expreso Al.Andalus" (Andalucia Express) which departs from Seville each week and for 5 day tour of Seville, Cordoba, Granada and Jerez de la Frontera. The price of the ticket includes the visits to these cities, meals at the finest restaurants in each one, "fiestas" and typical shows plus dinner and lodging on a truly special train that even includes a discotheque, video room, bars and the luxury and comfort of the finest hotel.
Another tourist train with similar characteristics is the "Transcantabrico" which tours the north of Spain.
The RENFE web site in English is -
http://www.renfe.com/EN/viajeros/index.html. Here you can access timetables and book tickets.
Looking to the future, Spain and Morocco have agreed to explore the possibility of an undersea rail tunnel to connect their rail systems. The 39-kilometre long rail tunnel would run from Punta Malabata near Tangiers to Punta Palomas, 40 km west of Gibraltar. At this point the Mediterranean Sea is only 300 metres deep. There are also plans for three connections with the rail system in Portugal.