The Kiruna mine is the largest and most modern underground iron ore mine in the world. The mine has an ore body which is 4 kilometres (2.5 mi) long, 80 metres (260 ft) to 120 metres (390 ft) thick and reaching a depth of up to 2 kilometres (1.2 mi). Since mining began at the site in 1898, the mine has produced over 950 million tonnes of ore.