Your legs will know after an hour: this is going to be a long day. From Saint-Jean-Pied-de-Port you start climbing almost straight away, up into the Pyrenees, and it never really flattens out. The steepest part comes early, up to Orisson after about 8 kilometres. After that you get space, wind and views. Somewhere along the way you walk into Spain, with no customs and no fuss. The last stretch takes you down through forest to Roncesvalles.
Before you set off, register at the pilgrim office, Accueil des Pèlerins on the Rue de la Citadelle. There you can pick up your credencial or a stamp, plus a list of albergues and stages. You can stay the night in Orisson, but book well in advance. This is the Route Napoléon, which you can only walk when the pass is open. In winter you go via Valcarlos. Take it easy, Roncesvalles isn’t going anywhere.