Nature Trail of 54 km one way. From Arlanzón to Monterrubio de la Demanda. Sections can also be done, such as the Pineda intermediate point, for example. It runs along the itinerary of an old railway, built in 1902, which transported ore from Barbadillo de Herreros to Villafría.
You will be able to enjoy incredible views, although it is full of ups and downs, and if you do the 109 km it may be hard since you have to climb the Puerto del Manquillo twice (round trip).
Although it is more common to do this route by bike, it is also possible to do stages of the Nature Trail on foot.
MORE INFORMATION on this website of the Sierra de la Demanda Greenway, where you will find tracks, guides, etc. https://laviaverdedelademanda.weebly.com/#
Download the Agalsa Brochure here https://sierradelademanda.com/folletos-agalsa/