The Puentéelos of the Basques · Puentedey

When leaving the tunnel, the route takes us to a trench excavated at the beginning of the XX century for the passage of the railroad. It is 80 meters long and up to 15 meters deep. It cuts the northern flank of the mountain range, and in its sedimentary walls are preserved fossils of micro and macrovertebrates. Here we can look for fossilized remains and refresh ourselves in a natural spring. From the nearby bridge we can see the gorge, the Nela River and the route of the old train.