Public railways serve all provincial capitals across Cuba.
The trains are quite outdated but the best train is the Tren Francés that runs from Havana on the northwest coast to Santiago the Cuba southeast coast. This route runs every night and the trains usually stop at Camaguey and Santa Clara.
There are also trains to other towns from Havana. These towns include;
Pinar the Rio
Frequency of travel is always varying hence always check ahead.
Booking is not available online and you have to buy the ticket at the station (sometimes they can ask for your passport).
I advise that you check the departure time at the station as it always changes and the time indicated on your ticket may differ from the actual departure time. ( There's always a chalkboard where departure times have been indicated).
There are three train classes
Lecheros- these trains stop at almost every town.
Regular- Are generally slow and have daily departures. Cost about $3 per every 100 kilometers
Especial- These trains are the fastest and have very few departures. Cost about $ 6 per every 100 kilometers.