Tracing the path of a mysterious and tragic mining railway through the leafy oak forest of the Sierra del Madero, climbing to the unique setting of the former Petra hematite mine, today hidden and beautified beneath a turquoise lagoon.

Basic Facts
	3,48 Km
	Ólvega. Soria. Castile and León
	Walkers, cyclists, suitable for people with reduced mobility
	Asphalt
	41.769808, -1.992505
	41.750693, -1.966064