Via Verde - Hueznar River
In the Sierra Norte Natural Park is this 18km-long vía verde (greenway) that follows the Huéznar river and the course of an old mining railway. The trains carried iron (hierro) from the mine at Cerro del Hierro to the station of Cazalla-Constantina, located 6km from Cazalla and 8km from Constantina, which was on the mainline.
A British mining company built the narrow gauge railway, which was used only for transporting minerals, in the late 19th century. The company also constructed houses by Cerro del Hierro which are still standing today. By the 1970s the mine at Cerro del Hierro became unprofitable and the railway was abandoned.
This is primarily a route for walkers, although cyclists can use the 8km section between Cerro del Hierro and the Los Molinos tunnel. It's not suitable for wheelchair users.
Soon after the beginning of the route at the Cazalla-Constantina station is an attractive, leafy picnic area, on the banks of the Huéznar river, called Isla Margarita. At Km 3 is the railway halt of Los Prados, where the course of the former mining railway crosses the train track still in use, which links the Sierra Norte with Seville.
One kilometre later the route crosses the road to San Nicolás del Puerto. This stretch is flanked by Mediterranean woodland typical of the Sierra, such as cork oaks, holm oaks and cistus scrubland. If you walk or cycle along the greenway in spring, you'll see the surrounding fields clothed in colourful wildflowers.
The route crosses the road again and then it passes through the river, where there used to be a bridge, but now you have to cross it via stepping stones. If the river is high, you may have to go up onto the road for a few hundred metres and take a dirt track to return to the vía verde.
The route climbs gently through the verdant valley of the Huéznar and there are some magnificent views of the countryside from the higher points of the railway embankments.
At Km 10 you pass through the Molinos tunnel, just over 100m long, and as you come closer to San Nicolás del Puerto the countryside opens out into gently rolling fields and dehesa woodland of cork and holm oaks. At Km 11 is an abandoned building that used to be San Nicolás del Puerto station.
At the station you have to take a small detour of less than 500m on the Constantina road to avoid a small section of the greenway that is in poor condition. You pass an attractive picnic area, the Nacimiento del Huéznar, which marks the source (nacimiento) of the river.
The last 5km stretch is in better condition and passes through more dehesa woodland. At Km 16 is the Cerro del Hierro, where there is a chapel that used to double as a school. Also here are houses that were inhabited by mining employees, built in a British colonial style and an architectural oddity in this Andalucian landscape. They are similar in style to those constructed in Riotinto and the Barrio Obrero in Huelva city, also for British mining employees.
The greenway ends at Cerro del Hierro, once an open-cast mine but today it has a more natural dramatic impact for its limestone rock formations. There is a signposted 2½km walk, the Sendero de El Cerro del Hierro, around the area.