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 top mentioned 'world famous five area' as well as a number of other geological phenomena. Reshuitang is located 30 km north of Jingpeng. 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'.

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

And a top ski
Arxan (Aershan) is the most often mentioned hot spring in Inner Mongolia. Better known for it's ski area (see Ten Best Places for Skiing in China), it 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).

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.