Alto de Erro and Alto de Mezkiritz.
Descending quickly and pleasantly down from the Ibañeta Pass towards Auritz-Burguete on the N-135 (beware of possible traffic), you have the illusion that a flat plank waits for you in Spain, once you have crossed the Pyrenees; on this first stretch along the Camino Francés the enthusiasm is increased by a red auspicious sign indicating the km needed to Santiago and by the awareness of crossing a territory made famous by the clashes between Arabs and Charlemagne's Paladins.
But... Never trust the first impression.
After passing the village of Aurizberri-Espinal, the road begins to climb up to the Alto de Mezkiritz, after which you descend to the village of Erro. Here begins a second climb up to Alto de Erro; they are neither long nor particularly hard and the numbers don't say much: less than 50 mt of elevation gain in 1 km, the first, and 150 mt in 3 km, the second, with some jerks at 7%. But if you travel with a lot of luggage and you have tackled the previous climbs (especially the Puerto de Ibañeta) too boldly, these climbs become tough too.
From here to Pamplona the descent is continuous and, if you are close to the end of the daily stage, it is a good idea to start looking for an "Albergue": the first is in Zubiri, farther there are some others, but not many and often they are full .