Khewra Salt Mines is a salt mine located in Khewra, Jhelum District, Punjab in Pakistan, about 160 kilometres (99 mi) from Islamabad and 260 kilometres (160 mi) from Lahore. It attracts up to 40,000 visitors per year and is the second largest salt mine in the world. Situated in the foothillsof the Salt Range, the Khewra Salt Mines are the oldest in the South Asia.
Salt has been mined at Khewra since 320 BC following discovery by Alexander's troops, in an underground area of about 110 square kilometres (42 sq mi). The main tunnel at ground level was developed by Dr. Warth in 1872 but has since been converted into a tourist resort. Khewra salt mine has estimated total of 220 million tonnes of rock salt deposits. The current production from the mine is 465,000 tons salt per annum.
The mine-head buildings have 19 stories, with 11 below ground. Only 50% salt is extracted and 50% is left as pillars to support the mountain. The salt-mine is 288 metres (945 ft) above sea level and extends around 730 metres (2,400 ft) inside the mountains from the mine-mouth. The cumulative length of all tunnels is more than 40 kilometres (25 mi).
Salt occurs in a Precambrian deposit in the form of an irregular dome-like structure. There are seven thick salt seams with a cumulative thickness of about 150 meters. At places the rock salt is 99% pure. Salt is transparent, white, pink, reddish to beef-color red. There are beautiful alternate bands of red and white color salt.
Discovery of the mine
It is said that when Alexander visited South Asia, coming across the Jhelum and Mianwali region, Khewra Salt Mines were discovered. The discovery of the mines, however, was not made by Alexander nor his "allies", but by his horse. It is stated that when Alexander's army stopped here for rest, the horses started licking the stones. One of his soldiers took notice of it and when he tasted the rock stone, it was salty thus leading to the discovery of the mines.
Afterwards this mine was wholly purchased by a local Raja and from that era to Independence of Pakistan this mine remained property of locally living Janjua Rajas who were sons of Raja Mal.