Epic drone view of a dangerous, hollow mountain in Greece

The sign reads: "Caution! Danger! Invisible ditches" and this means that one step can be ... fatal.
We fly over the mountain of Attica which ... it is better to see it only from above as the walk in it is extremely dangerous. The depth of the main well reaches 100 meters!
At the beginning and until the middle of the last century, an extremely precious metal, iron, was produced in this place.
We read about it in "urbanspeleology.blogspot.com": The Italian-made iron mines of Grammatikos belonged to the Soutsos family, while the testimony of a local elderly man also tells us about an English company. They started operating around 1880 with endless length galleries on various levels, deep vertical wells, bridges, while the network of the railway line that started from the site, reached -according to different sources- to Ramnounta, Sesi or Limniona. transporting the ore to the ships.
The systematic operation of the facilities must have been abandoned around 1920, as their operation was deemed unprofitable. According to others, they operated until 1930, while the locals say that in the years of occupation (1940) people and property fled the railway line, except for ore. Therefore, according to the testimonies, the mines may have been used occasionally during the 1920s, 1930s, 1940s, while they operated regularly in the 1910s, which is confirmed by inscriptions engraved on the bottom of a large well of the facility, which proves the presence of people there. certainly until 1914 ".