Does anyone know if there are any regional trains or buses that go from Santiago to Bilbao?

The trains seem to go inland and takes a very long time. :p

I think ALSA/Enatcar has bus service along that route. You may have to change in Santander.

There's also FEVE (Ferrocaril Español de Via Estrecha). You may have to bus it to O'Ferrol or Betanzos. It's slow and expensive but the scenery is great!

The ALSA bus company runs a bus from Santiago to Ferrol (at 0915, 1100, 1330, 1430, 1600, 1800, 1930 & 2100 on weekdays; 0915, 1100, 1330, 1600, 1800 & 2100 on Saturdays; & 0915, 1330, 1800, 1830, 1930, 2100 & 2200 on Sundays). From Ferrol, you can get a train on the FEVE narrow-gauge railway right along the north coast to Bilbao and beyond (several services per day). I think you may have to change at various points along the way, but I'm not sure as I haven't yet done this journey myself (am planning to next month!) - see the FEVE website www.feve.es ; ALSA also have a website ( www.alsa.es ) but I found it difficult to use as it seems to get tangled up in knots when you move your mouse around the screen (you'll see what I mean!) so I got the above timetable by e-mailing them. Hope this is helpful...