Note that Peñasieta, AND the albergue, are not on the camino. Signs point the way and see the albergue notes on how to get a hold of the keys at the bar on the road.
From Peñasieta, the climb begins. The preferred, and more beautiful, route is along the trail so if you spent the night in Peñasieta avoid the temptation of following the road (even though it will get you there). The elevation gain is about 600 meters up to the Alto de Palo, with a few particularly steep sections along the way.