Ojos Negros iron mines Curiosity · Ojos Negros, Jiloca, Teruel Old iron mining operation that gave rise to the Vía Verde de Ojos Negros. The Compañía Minera de Sierra Menera began extracting ore at these mines in Ojos Negros (Teruel) in 1906, and within barely seven years came to account for 10% of national iron production. To transport it to the port of Sagunto it built a 205-kilometre narrow-gauge railway, the Ferrocarril Ojos Negros-Sagunto, which avoided other companies' tariffs. Mining activity continued until 1987, when the company was dissolved; the railway, closed in 1972, is today the greenway that follows the historic route. The company's records are kept in the Archivo Histórico Provincial de Teruel. Photo: LBM1948 (CC BY-SA 4.0) What to see and do in Ojos Negros