Trailhead: mountain hut of Belagua.
Slope: 1320 metres.
Time: 5h (climb). Total: 10h.
(Very important: in winter is very hard and long: 7 hours to summit-you must think that the hour to begin the climb is very soon but not descent in the night).
From the mountain hut (refuge) of Belagua (1428m), take direction E-SE to Ezkilzarra through the narrow mountain pass. We continue to the left through the woods. There are 2 routes:
a)-Valley of Lapazarra: follow the marks of white and red of the GR12 bordering the Lapazarra for the left to the Col of Lapazarra (1660m, 1h45min). Now we come down to the valley of Ukerdi to the Col of Larreria (1644m, 2h).
b)-South of Lapazarra: come down to the valley and turn to the south. We follow the crest over the valley and under Lapazarra (1786m) to the Col of Larreria. For this point is possible to go to south and continue for the routes of Linza or Western ridge.
From Col of Larreria we continue for the valley of Ukerdi with many attention to the Col of Lhurs(2990m,4h) in the north of La Mesa. We follow the evident path and finally through a short climb grade I in the ridge we reach the summit.
In winter: ice axe and crampons.