World's top 5?

Inner Mongolia (or Nei Mongol) is another of the huge automonous regions of China. Inner Mongolia borders Mongolia, to the west of Beijing. H

In the regions capital Hohhot one can stay at the Water Moon Hotspring hotel, tripadvisor states, though I'm not totally certain whether or not that really is the case.

World famous Wiener
Apparently it was once stated on internet that once used to state:

'There are many hot springs in Inner Mongolia, including the world famous five'.

However, whether this info is now considered useless or whether it's just a case of the internet evolving in directions unknown it remains a question. However if true, the hot spring named Wiener Creek is just one of those 5. The Chinatravel website used to add to the above sentence:

'Located in the middle of Xilu Wei Nahan Daxinganling mountains mountains in the Wiener River mineral field, there are seven springs arranged in the context of more than ten square meters, and some very clear and clean spring water, some were white, some brown-yellow, water temperature were 2 ° ~ 6 ° C, the water quality with world-famous French spa Vichy comparable. They generate strong in much of ancient Tertiary volcanic activity, was Mongolia, Oroqen, Ewenki called “Shen Shui.” Have been developed using universal spring, spring stomach, acid springs, the heart of spring (above 4 springs for drinking spring), the first spring, ear, nose spring, seven medicinal springs bathing spring, about 40 tons per day and night flow can be bath treatment for 45 thousand people used to drink. Mineral water contains more than 230 kinds of minerals, on dozens of chronic diseases have a significant effect'.

Natgeo
The UNESCO designated Hexigten National Geopark contains the Reshuitang thermal spring, another of the mentioned 'world famous five' as well as a number of other geological phenomena. 
Reshuitang is located 30 km north of Jingpeng. Jingpeng is the site of a famous railway pass. According to tripadvisor there is a hotel named Yangguan Hot Spring Hotel. 
More on Reshui can be found here including this last sentence:

'At present, there have been 10 hot spring sanatoriums. This hot spring town which is beside the mountain and water has beautiful scenes'.

This website adds:

'The hot spring was developed 1.000 years ago.In the Liao Dynasty Emperor Taizong and his successors had baths in the spring water In 1686, Emperor Kangxi of the Qing Dynasty visited the hot spring and took a bath. The site where the Qing emperor bathed remains today'.

Visitors though might want to look up the info on tripadvisor. As this recent poster experiences:

'Unfortunately the hot springs in the town square have been closed for many years and the hot springs in a big hotel with a hot swimming pool were also closed.

...

The huge stone at the entrance of the town announced that this town is famous for hot springs, but no hot springs were open, apparently they only open in May. So don't go there before May, at least I could find a hotel with hot baths, so that was my hot springs experience!! '

More fame
On Ning hot spring, another of those famous 5, there is nothing additional mentioned.

On the hot spring of Liangcheng located near Daihai Lake, Liangcheng county

'Located in the mountains of central Inner Mongolia, Han Liangcheng Daihai very hot, because legend of Emperor Kangxi, when the patrol side spring mount thirst in this plane, also known as “spring plow horse,” Temple has been built Yongxiang, aristocrats, celebrities Ascot and the monk Lama bathing resort of convalescence. Underground water is a sodium bicarbonate-based weak mineralization of water, water temperature 37 ° ~ 38 ° C, rich in lithium, zinc, strontium, radium, metasilicate, selenium, iron, magnesium, sulfur and other chemical elements and minerals substances, rheumatism, rheumatoid, skin diseases, low back pain, dry skin and other diseases have a significant effect'. source

Apparently there's now a hotel named Daihai Hot Spring Hotel. What can one expect? 

'Daihai Tourist Area is mainly composed of three parts - Daihai Hot Spring Resort, Daihai Tourist Resort and Daihai Hot Spring Hotel. In recent years, great investment has been made on the Daihai Scenic Area. It has built several hotels, Daihai Tourist Center, Daihai Spa City, Daihai Ski Resort and Daihai Cultural Tourism School and other projects. Now the 130 square km area around Daihai Lake is a suitable place for leisure, conference and sightseeing.
Daihai Hot Spring Resort( or Daihai Spa City) is just 500meters north of Daihai Hot Spring Hotel, about 10km in the west of Liangcheng County. The Daihai Hot Spring Resort is a Japanese style garden building with 4 indoor hot spring pools. The Daihai Spa City is located at the foot of Manhan Mountain with plentiful hot spring resources. The hot spring temperature is mild and comfortable ranging from 40 degrees to 60 degrees. There are 17 kinds of minor elements in the hot spring water. It is good for the treatment of the pain in low back and legs with rheumatism. The Daihai Hot Spring is often regarded as "Holy Hot Spring Beyond the Great Wall".

The accompanying photo's though reveal a rather dour inside soaking area with yes a fake Japanese touch. This blogger has visited here and leaves this strange comment:

'Otherwise I loved Liangcheng (well one of the small villages surrounding area): we stayed in a Japanese style hotel with its hot springs, almost every family has its own dairy cow, and it’s incredibly easy!'

And a top ski
Arxan (Aershan) is the most mentioned hot spring in Inner Mongolia. Better known for it's ski area (see Ten Best Places for Skiing in China), Arxan is apparently also home to a hot spring museum. I'm not totally sure if this is what a museum means:

'The museum will feature different sites including the Arxan hot springs, volcanoes, as well as bizarre lakes and stones.

The museum locates outside Arxan city, a Chinese frontier town southwest to Daxinganling Region, the city boasts the largest and best-kept volcano basalt physiognomy and the world's largest hot springs used for drinking and bathing.

One of the area's most spectacular sites is a concentration of 48 hot springs that are classified into three different types and four different temperature levels'.(source)

Another aspect that makes Arxan hot springs famous are that it is the largest group of radon hot springs in China (source, link not functional). It is also noted that the local stream is ice-free during winter (source).

Despite all the factual claims to fame there seems precious little photographic evidence of any soaking available. A couple of indoor sites fake Japanese style. One going by the name Haishen Hotspring Hotel (located on Hotspring street). Though this seems attractive enough:

Arxan seems a great place to do nothing:

'AereShan is a famous Mongolian hot Springs area. There is a hot spring for every body organ. The area is all beautiful mountains. We went for a drive into the mountains and wow. Wild flowers. Rivers. Mountains. There is not much to see in the town, so this is an area to relax, use the hot springs, and learn the history'.

That description seems quite compelling. Whether or not this will remain is possible not the case. A recent news article suggested that Aershan will be the focus of Sino-Icelandic geothermal investment.

Pilgrims and Soakers

The bathing building of Chiu (source).

Ngari
One of China's western-most administrative divisions is the prefecture of Ngari, still part of the Tibet Autonomous Region, even though it's no less than 1600 km west of Lhasa, Tibet's capital.

Sparsely populated (the 77,000 population can each claim 4 km2 per person), it's a wonder there is any information on hot springs in Ngari prefecture. 
That would have been the fact if the Tibetan holy mountain of Kailash would not be in the eastern part of this prefecture. Walking round this mountain (a kora) is part of Tibetan tradition which has attracted a number of travelers to do likewise. And so, a few hot springs thus stumbled upon have made it to the internet.

A soaking pilgrimage
By far the most mentioned soak in this part of Tibet is the hot spring area of Tirthapuri, a not so Tibetan sounding name. 

Located in Burang county, conveniently situated, it's not too far away from the other pilgrim places of both Kailash mountain (just 80 km) and Lake Manasarovar and it's considered as the third (and final) leg of the trio kora.

This tour site provides more background on the religious significance:

'Tirthapuri' to Hindus, 'Tetapuri' to Tibetans, is the holy power place of the Hindu Goddess Parvati, the consort of Lord Shiva. It is the power place for the Goddess Bajra Barahi and Tara to the Buddhist. The hot spring here is the main holy sight for the pilgrims and it represents the female element, while Mt. Kailash, the male. 'Tirthapuri' considered the third holiest place in Ngari. This is where Heruka subdued Rudra, and according to Tantrism, this holy place is considered one of the 24 major power places on the sub-continent. It is renowned for its blessing of red and white earth from the hot spring'.

Hot springs female, mountains male?

Photo by Katey G. simply entitled

'Tirthapuri hot springs'.

Another Nepali tour site adds:

'Tirthapuri - a region known for medicinal hot springs and a geyser where in a story of Hinduism demon lost the fight to the god was burnt to ash, righteousness finally overcome the unrighteousness'.

Elsewhere on the web, one can find out what to expect when soaking. Here's a snapshot:

'Located on the north bank of the Sutlej River, the Tirthapuri Hot Springs fill the barren landscape with steam. Pilgrims typically come here after completing the Kailash pilgrimage. They bathe in pools fed by the sacred springs, then visit the cave and monastery associated with Guru Rinpoche. Prayer flags stretch across the river gorge and chortens (stupas) add color to the landscape'.

Unfortunately, this otherwise good website has little on the soaking experience itself.

Despite this report from 2006 claiming the soaks to be 'extremely hot', LP's Tibet guide adds that the hot springs are getting weaker and weaker every year, though possibly this refers to the accompanying geyser. Then again it may be the reason why there's little recent info.
The Fp Tibet guide mentions that the Tirthapuri waters are clean to bathe in, which is a re-assurement of sorts. It adds:

'From one of the blowholes, however, small white flecks or 'pills' of lime can be found. Tibetans strain the water for these and use them for medicinal purposes, since they are said to have a consecrated power to cure disease'.

Beauty in Divine has an extensive posting on Tirthapuri, though not first hand?

Around Kailash
Nearer Kailash mountain are a number of other hot springs. Chiu (Chiyu or even Quhu) hot spring seems to be the most often frequented. Located near the monastery with the same name this hot spring actually has its own bathing building complete with glass roof (see top picture).

The village of and surrounding Chiu Gompa.
Note the bathing building on the right near the building (source).

That said, soaking itself seems less than desired:

'As it turned out all the baths either had big gaping holes in them, and none had plugs. They had never been cleaned and the hot spring water came trickling through a spout from a wall. Michael managed to stuff up his drain hole and had a happy full bath. Paul and I had no success. Although feeling sick, I was determined to keep calm as I knew I was extremely privileged to be on the top of the world at one of the holiest sites'.

For a different experience, look at the photo (below) by Rolf Gross, dating from 1995 probably before development of the site took place.

'Here you see Jeroen, Marc, and me soaking in the pleasantly warm water. Notwithstanding that there was no mirror I even shaved! The three women waited on the side. Later I found out that after Padru had also taken an extraordinary dip — Tibetans like the Ladakhi are loath of water — Barbara and Katrina had stripped and jumped in....'

Not so far away from Chiu (21 km north of Raka, but closer to Kailash) is Tagyel Chutse (Tso) or alternatively the King Tiger hot spring. The LP Tibet guide adds:

'... a small collection of gushing geysers, bubbling hot springs, puffing steam outlets, and miscellaneous smoking holes in the ground'.

John Town has a fine set of photo's. It's unclear whether or not soaking takes place ... 

Elsewhere
With the single reference (1), Qoipur (Burang) is something of an anomaly. Little regard for soaking, though there is a geyser which is rumoured to have blasted 900m high, once in 1975. Seeing is believing?

The hot springs of Gyagar are located (link not working) just inside Ngari prefecture. Little other info.

[Updated August 2015]

Notes:
(1) refers to the anonymous publication entitled Travel Guide to Tibet of China, published in 2003 by China International Press.