Tanzania's President John Magufuli has officially inaugurated the Great Mirerani Wall, built in the north of the country to prevent the theft of tanzanite, a rare gemstone.
In September, Mr Magufuli ordered the military to build the wall, which is 24km (15 miles) long, in order “to control illegal mining and trading activities”.
The blue-violet tanzanite gemstone is found only in the East African state.
This is the first time Tanzania has built a wall to protect its mines, and some believe that other countries grappling with smuggling may also build them.
