This is an interesting route to the summit of Moncayo, specially if we want to search a less frequented route. The final ramp is long from the collado de Castilla (1950m) and the path is not very good. In many times is useful to descent from the summit if we've climbed across the normal route, because the trailhead is the same in the sanctuary or vice-versa.
The collado de castilla is the frontier between the Spanish regions of Castilla and Aragón, and the provinces of Soria (Castilla) and Zaragoza (Aragón). It's as well the point of entry of the routes from Agreda (Soria).
See the main page to approach to sanctuary of Virgin of Moncayo (1620m). The trailhead is at 500m before the sanctuary in the parking of Haya Seca (1565m).
The route begin in a great stone with some red paint (difficult to read nowadays) following the cairns in the stony path of the forest. The path is good and evident to follow in West direction, even with a little descent in a few of meters. After a hut in ruins we'll exit of the forest in a cross-path. In right side we'll see a path from the track of access to the parking but we'll turn to left in direction to the evident col between the Moncayo (left) and Peña Negrilla (right). After some walks with a lot of vegetation we'll reach the Collado de Castilla (Castilla's col, 1950m, 1h15') with a border-stone.
For the peak-baggers in right side is near the summit of Peña Negrilla or Moncayo de Castilla (2118m) and it's possible the climb in 25 minutes
We'll turn now to left side to approach to the bottom of the great west ramp of Moncayo, searching the cairns to get the path. The path is not always present, with some stones, but the cairns are always very useful to follow to the summit with important slope. In the summit of Moncayo (2315m, 2h10') generally we'll descent across the normal route to sanctuary.