The Khewra salt mine, the second largest in the world, is a warren of 40 kilometers of tunnels housing an illuminated mosque made from salt rock, an electric train and even an asthma clinic.
The mine 100 miles south of Pakistan's capital Islamabad is the largest and oldest salt mine in the country, drawing up to 250,000 visitors a year.
Khewra was discovered back in 320 BC by Alexander the Great's troops, but trading started in Mughal era in the sixteenth century.
Scroll down for video
Remarkable: A man praying in a mosque made of salt rock, complete with two minarets. at the world's second largest salt mine in Khewra, Pakistan
Subterranean wonderland: The Khewra salt mine is so large that it includes a mosque, an electric train and a clinic offering salt treatments for ashtma
The main tunnel at ground level was developed during British rule by Dr. Warth, a mining engineer in 1872 and has been flourishing ever since.
An electric railway has been working in the mine since the 1930s. It once hauled extracted salt from the mines, but now brings tourists in to marvel at the salt formations.
The mine is still the largest source of salt in Pakistan with more than 350,000 tons produced per year, excavated at 18 different working levels.
More...
Inside New York's most expensive home: Three-floor penthouse with 16 bedrooms goes on sale for 125 million dollars
Thanks dad: Orphaned chimpanzee who is now star of new Disney film pictured embracing his adopted father who saved him from death in the jungle
To keep the vast mine from collapsing, only fifty percent of the salt found is mined in the 110 square kilometre area.
There are seven thick salt seams with cumulative thickness of 150 meters. In places rock salt is 99 per cent pure.
Beautiful colours: The mine has become a major tourist attraction thanks to its mix of white, pink and red salt formations
Magical: The atmospheric mines draw up to 250,000 visitors a year
Vast: The mine 100 miles south of Islamabad is the largest source of salt in Pakistan
Salt caves: Visitors admiring the natural marvel of formations deep underground
Marbled effect: In places rock salt is 99 per cent pure with a variety of shades depending on the seam
Working mine: A miner leaves the ancient caves which were discovered in 320 BC
Historic: The main tunnel at ground level was developed during British rule in 1872
Pink hue: Inventive souvenir sellers have managed to make electrical goods such as lamps out of the salt rock
The cavernous tunnels have alternate bands of translucent, white and pink coloured salt.
As well as the traditional mining, for the past three years there has also been an experimental asthma clinic at the mine, attracting patients from all over the world.
Salt caves are seen by some as an alternative to drugs as asthma suffers can benefit from inhaling antibacterial salt particles to clear the lung passages.
Located deep underground in the mine, the asthma clinic has 12 beds and a reception area decorated with lamps made from salt.
The largest mine in the world is the Sifto Canada salt mine in Ontario.
Take a tour inside the Khewra Salt Mine
Cavernous: A miner, silhouetted by a gas lamp, lifts rock salt after breaking it from a wall
Rabbit warren: The cumulative length of all the tunnels is more than 40 km