Before starting this trip we will take into account that its realization is limited to certain times of the year. In rainy season and thaw, the passage through the gorges is more dangerous and complicated by the excessive flow of water. On the contrary, in the summer months, the channel of the Serna stream is lower.
From Lándraves we crossed the Trifón River by a bridge. We take the narrow path on the left (GR-85), the stream that will be on the left, will be our travel companion.
After a few minutes of smooth march the road fits into the first gorge. It is a complicated step when the channel of the stream is high and, sometimes, it is possible that we have to return. We begin a gentle ascent until we reach the second gorge; on the way we will enjoy several small jumps and rapids.
We thus arrive at the second sickle; they are almost two hundred meters long between challenging vertical walls of more than one hundred meters of height. For its scarce four meters in width, the course of the stream and the path runs, through which we will have to pass from stone to stone.
From here we can return or continue the march to Munilla, a rural town that stands out for its original location and its peculiar Romanesque church. To reach this population we will ascend slowly to the right, passing between trees, meadows and livestock farms. We will return to Lándraves for the same itinerary.