ALAN HARRISON schrieb:

Use Euskotren metric gauge train to Hendaia and SNCF train from Hendaye.
Walk 30 metres between stations.

San Sebastian is also served (probably less picturesquely but more quickly)
by Spanish mainline trains. The mainline track between Hendaye and Irun is
dual gauge (standard gauge SNCF and broad gauge RENFE), so that Spanish
trains can finish their journey in Hendaye and French ones in Irun. (Comment
based on experience more than a decade ago, when passport controls were
still in palce between the two countries.)

Sure but there are few renfe trains to Hendaye. IIRC, regional RENFE
trains don't go there.

Regards, ULF