The Khewra Salt Mine (or Mayo Salt Mine) is located in Khewra, north of Pind Dadan Khan, an administrative subdivision of Jhelum District, Punjab Region, Pakistan. The mine is located in the Salt Range, Potowar plateau, which rises from the Indo-Gangetic Plain. It is Pakistan’s largest, the world’s 2nd largest.
The mine is famous for its production of pink Khewra salt, and is a major tourist attraction, drawing up to 250,000 visitors a year. Its history dates back to its discovery by Alexander’s troops in 320 BC, but it started trading in the Mughal era. The main tunnel at ground level was developed by Dr. H. Warth, a mining engineer, in 1872 during British rule. After independence, the Pakistan Mineral Development Corporation took over the mine, which still remains the largest source of salt in the country, producing more than 350,000 tons per annum of about 99% pure halite. Estimates of the reserves of salt in the mine vary from 82 million tons to 600 million tons.
The Khewra Salt Mine is uncovered inside the base of a thick layer of exceptionally collapsed, blamed, and extended Ediacaran to early Cambrian evaporites of the Salt Range Formation. This topographical development comprises of a basal layer of glasslike halite, which is intercalated with potash salts. This basal layer is overlain by gypsiferous marl, which is covered by interlayered beds of gypsum and dolomite with rare creases of oil shale. These layers are overlain by 200 to 500 meters (660 to 1,640 ft) of Neoproterozoic to Eocene sedimentary rocks that have been elevated and dissolved alongside the Salt Range Formation to make the Salt Range at the southern edge of the Pothohar Plateau. The Ediacaran to early Cambrian evaporites of the Salt Range Formation have been pushed toward the south over Neoproterozoic to Eocene sedimentary rocks by numerous kilometers, which structurally fused pieces of the hidden more youthful layers inside these evaporites.
Khewra Salt Mine is a major tourist attraction, with around 250,000 visitors a year, earning it considerable revenue. Visitors are taken into the mine on the Khewra Salt Mines Railway. There are numerous pools of salty water inside. The Badshahi Masjid was built in the mining tunnels with multi-colored salt bricks about fifty years ago. Other artistic carvings in the mine include a replica of Minar-e-Pakistan, a statue of Allama Iqbal, an accumulation of crystals that form the name of Muhammad in Urdu script, a model of the Great Wall of China, and another of the Mall Road of Murree. In 2003 two phases of development of tourist facilities and attractions were carried out, at a total cost of 9 million rupees. A clinical ward with 20 beds was established in 2007, costing 10 million rupees, for the treatment of asthma and other respiratory diseases using salt therapy. The “Visit Pakistan Year 2007” event included a train safari visit of Khewra Salt Mine. In February 2011 Pakistan railways started operating special trains for tourists from Lahore and Rawalpindi to Khewra. For this purpose, the railway station of Khewra was refurbished with the help of a private firm.