(S) Take the GR®11 towards the bottom of the valley; the path is initially flat but then gradually climbs, first through woodland before reaching a section that becomes increasingly rocky. After a final short climb over scree (which is not difficult and is well signposted), you’ll reach the Col d’Estos or Puerto de Chistau.
(1) Continue down a lovely descent to reach the Barranco de Chistau stream.
(2) Cross the stream, keep to its right bank, and pass close to the Añes Cruces refuge. Carry on, still descending, until you reach the Puyarueco refuge.
(3) Continue the descent to Bordas de Viados.
(4) Walk through this small hamlet with a few buildings and take the track leading to the Viados Refuge (E), today’s destination.