Salt of the earth: The 5,000-year-old mines inside caves and tunnels in Turkey which are still in use today
Salt mine is located outside of Cankiri city in northern Turkey
It was first mined by ancient race called Hittites in 3000BC
Despite its age it still produces 500 tonnes of salt a year
Photographs were taken for National Geographic contest
More:Salt of the earth: The 5,000-year-old mines inside caves and tunnels in Turkey which are still in use today | Mail Online
