Hiking along the course of the Tinto River
“The Tinto River… a trip to Mars”
Its red waters are characterized by a pH between 1.7 and 2.5 (very acidic) with a high content of heavy metals (iron (mostly), copper, cadmium, manganese, etc.) but with oxygen, since the organisms that exist in the river are mostly photosynthetic. However, since before the appearance of man, microorganisms that feed only on minerals and adapt to extreme habitats live in its waters; such organisms are both prokaryotes and eukaryotes, including among the latter some species of fungi and algae endemic to the river. For this reason, NASA chose it as a habitat to study due to its possible similarity with the environment of the planet Mars. An experiment with the participation of the Higher Council for Scientific Research (CSIC) and developed in the Tinto River (Huelva) has confirmed the possibility that certain types of organisms can survive under the restrictive conditions of the planet Mars. The Tinto River is the subject of NASA study.
Taking the C-421 regional road, in the direction of Minas de Riotinto-Nerva, we will turn off to the right at the height of the South Dam or Balneario reservoir, taking the access signposted as Zarandas (1).
This access runs along the slopes of Cerro Los Tres Águilas, which forms part of the Sierra del “Madroñal”, where the old Pyrite Chimney is also located, used to expel toxic gases from the smelter and which we can distinguish on the right of our path (2). At this point there is a detour to the right (3), which leads to the old mineral smelting plant.
From this point on, we can enjoy a whole range of landscapes that represent the best of the years when mining was in British hands.
In this way, we can see old slag heaps – remains of molten mineral -, cementation ponds, railway tracks for transporting mineral to Huelva, etc…
Continuing along this path, we will reach the old railway station of Zarandas, where there are a series of warehouses in which some examples of machinery from the period are preserved along with the tourist railway.
At this point, we must leave the vehicle and continue on foot or by mountain bike through the old mining operations, looking for a steep slope that corresponds to the depression where the river Tinto runs. At this point the railway begins a linear journey of about 84 km to Huelva.
Throughout the route you can enjoy wonderful sandy beaches, steep meanders, closed gorges, as well as numerous abandoned stations, tunnels and bridges, among which the Solomon Bridge and Tunnel (5) deserve special attention.
However, we must especially recommend the route for its impressive scenic wealth, as well as for its historical and heritage value for travelers interested in these aspects.