If you drive on the highway from Kulob towards Vose, it Khoja Mumin slopes are steep at the base and the exposed salt walls reach as much as 500m in height. Stripes of salt caused by the frequent alternation of pure stratum (5-15cm wide) and dark ones (enriched with various clays, about 1.5cm thick) are easily visible. Salt has been accumulating here for at least 20,000 years.
The famous Venetian explorer Marco Polo, after visiting this area several hundred years ago, wrote: Salt here is solid and it is broken with big spades; there is so much salt that it would be enough for everyone till the end of the world." According to geologists' recent estimations, Khoja Mumin has more than 30 billion tons of salt reserves. Khoja Mumin is the second largest surface salt hill in the world after Kuhi Namak Mountain ("Salt mountain") situated in Iran, which is 1,200m high.
Khoja Mumin salt massif
Khoja Mumin is also famous for more than 160 medicinal springs, which could be used for sanitariums and resorts. One other wonder of Khoja Mumin is its caves, the largest of which is almost 350m long (it is assumed that it is actually more than 1km long but to confirm this would be extremely difficult because the main entrance is full of narrow, flooded holes). The caves are famous for their "melodiousness" - wind passes between the long, thin salt stalactites hanging from the ceiling and the stalagmites decorating the bottom of the caves and generates wonderful and unusual sounds. These caves were formed from sodium chloride deposits displaced from the depths of the mountain.
The largest caves are 8-10m high; and streams run through them into the mysterious depths of the mountain only to reappear at its base. Colonies of bats and various insects dwell inside the caves. There is very little precipitation in the salt mountain area.
The rains tend to stop in May and the weather remains warm and dry until November. However, salt streams flow from the mountain as if Khoja Mumin is forever shedding tears... Where do they come from? In the caves, the exact number of which is not known, one can find interesting salt sculptures looking like towers, colonnades, mythological creatures and mushrooms, all constructed by nature, but their lifespan, like that of the caves, is not long and as the salt is washed away from their foundations they collapse, unable to sustain their own weight. The abundance and variety of vegetation on the surface of the mountain is surprising.
There are pistachios, maples, hawthorns, buckthorns, pear-trees, junipers, and many bushes and herbs. How can plants which cannot withstand even the lowest levels of salinity, grow on the salt mountain? How was this salt giant formed in the first place and how did it come to have a soil cover 2-3m thick? Geologists think that many years ago there was a large warm sea in Central Asia, which gradually shrank due to tectonic movements and changes in the climate, causing deep lagoons to appear, one of which was situated at Khoja Mumin. For a long time this lagoon stored the seawater, allowing it gradually to evaporate, leading to the accumulation of salt here. Later, through tectonic movements, mountains were formed, and the layers of sstt .tarn .the bottom of the dried-up lagoon were lifted up and formed Khoja Mumin. The soil appeared on this salt mountain from dust particles brought by the wind.
In former times, rock salt was extracted here using special hammers that could cut out blocks about 1m long and 20-25cm thick, and this served as a good exchange commodity. Nowadays, salt plants operate at Khoja Mumin extracting salt through the natural evaporation of concentrated salted water in small square holes. The dry remains of the brine contain 98% sodium chloride of the highest quality. After salt collection, water from the streams is returned to natural pools and so it continues from May till September. Saltlick, a salt fodder for domestic cattle is also extracted here.
Climbing to the top of Khoja Mumin is not easy because the domed surface is pitted with ravines, craters and holes 200m or more in diameter. Most of the hollows look like vertical wells or shafts with black, gaping mouths. Stones thrown into the wells can barely be heard landing. Moreover, there are sharp salt peaks, from several centimetres to 1.5-2m high, on the steep craters' walls which cover huge areas, making them almost impassable and very dangerous. Geologists eye-witnessed an accident in which a wild boar fell from a cliff and was impaled on a salt "knife".
Another salt mountain, Khoja Sartez, is located not far from Khoja Mumin, and its salt deposits are much larger than Khoja Mumin's, more than 40 billion tons! Khoja Mumin salt mountain represents an extremely interesting natural laboratory for hydro-geologists, soil scientists, botanists, ecologists and of course for tourists who love the unusual and exotic.