I think I must have gone up the one
@Vacajoe describes. The reservoir was at its lowest for 50 years, so I was almost walking along the old path by the río Aragón, past farmsteads usually covered in water.
And then on an old path near the Urbanización Náutica de Leyre, up to the monastery. Quite sharply up - around 200m up in 1.5km, but through lovely lovely woods, with occasional views of the monastery higher up in its solitary splendour.
By good luck, nearing the top as I was flagging slightly and thinking I was rather hungry, I met Fray Javier de Laguna out for a postprandial stroll. He was the brother hospitalero and soon had me being given an excellent lunch in the monks' refectory before showing me to the comfortable pilgrim quarters.
I loved Leyre: surrounded by woods, Gregorian chant with vespers and lauds, the rule of St Benedict read as we ate our silent dinner, a full moon over the reservoir and views back to the peak above San Juan de la Peña.
The next day was good too, through the Foz de Lumbier and on to Sangüesa.