Most people arrive in Europe at one of several major airports, usually Madrid, Paris, Barcelona, or London.
There are transportation links to SJPdP from Bayonne, Pamplona (the Conda bus is seasonal only), and Pau. These three centers are connected to the rest of Europe by plane, train, and bus.
The closest airport to SJPdP is Biarritz (BIQ) (Biarritz/Anglet/Bayonne) with connections to London, Paris, but not Madrid. There is a train and bus service from Bayonne to SJPdP.
San Sebastian (EAS) airport, located in Irun, has flights to Madrid. There is train and bus service from Irun to Bayonne.
Santiago Labacolla Airport (SCQ) is connected to many centers in Europe including Madrid, Paris, Barcelona, and London. Santiago is well connected by high speed rail and bus services.
Airports
AENA manages airports in Spain. See each airport for destination and airline information.
http://www.aena-aeropuertos.es/csee/Satellite/HomeAenaAeropuertos/en/Home.html
Biarritz Airport (BIQ)
http://en.biarritz.aeroport.fr/
Paris Charles de Gaulle (CDG) and Orly (ORY):
http://www.aeroportsdeparis.fr/ADP/en-gb/passagers/home/
London Heathrow (LHR)
http://www.heathrowairport.com/
London Gatwick (LGW)
http://www.gatwickairport.com/
London Stansted (STN)
http://www.stanstedairport.com/
London Luton (LTN)
http://www.london-luton.co.uk/
London City (LCY)
http://www.londoncityairport.com/
Trains
Renfe
http://www.renfe.com/
SNCF
http://www.sncf.com/en/passengers
I traveled from Vancouver to London Heathrow with Air Canada, transferred by National Express Bus to London Stansted, flew with Ryan Air to Biarritz, took the #14 Chronoplus Bus to Gare Bayonne, and the SNCF TER 62 train to SJPdP.
I went by Monbus from Fisterra to Santiago, Renfe train from Santiago to Madrid, flew with Easy Jet to London Gatwick, transferred by bus to London Heathrow, and onward to Vancouver. I could have flown to London from Santiago.
I stayed overnight in London both ways.