In ancient times the term 'taking the waters' was commonly used. Water therapies in natural hot springs were used not just to cleanse and rejuvenate, but also to heal. This is still being done today.
The earliest civilizations used the hot springs as far back as 4,000 B.C. often for religious rituals but also for healing. These kinds of rituals were very popular in Egypt, Mesopotamia, China, Taiwan, India and Crete. In the 16th century Europe rediscovered the ancient Roman spa culture in towns like Bath. People used to take the hot water in natural hot springs or baths. While today it is taken in hot tubs or spa tubs in spa salons. However, not underestimating the relaxing and healing effects of these tubs, I believe that nothing can take the place of a natural hot pool in terms of its healing, rejuvenating power in a natural environment, which surely leaves its positive impacts.
If we go a little into geography, a hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are hot springs in many locations all over the crust of the earth. Armenia is not an exception.
There is one located in the town of Hanqavan. The local people simply call the natural hot pool Taq Jur (meaning Hot Water in Armenian). They also assure that once you take it, you will feel better for a couple of years! Whether this is true or not, you will need to try it to find out. However, the healing power of the water is proven for many times. It can heal muscle injuries, back pains, joint pains and more.
More famous and nicer hot springs can be found in Karvachar, a northern part of the strip of land which separated Nagorno Karabakh from Armenia in Soviet times. This territory is mountainous, with forests, hot springs, rivers and ancient Christian monasteries. This place is really too isolated. It is bounded to the north by the Mrav Mountains and can be broken into three river canyons. The canyon that connects northern Karabakh to Armenia is not visited often, except for a visit to Davidvanq, a sprawling Armenian monastery of 9th century.
The hot spring is located 8km past Karvachar town, right by the river. You can control and regulate the temperature by covering the spring with a big metal column in the water to increase the heat. If you let it, it will get VERY hot. Removing the cover will cool the temperature down as the water shoots out of the pool. The spring gushing is quite noisy, despite the surrounding serene nature, thus you might need earplugs to keep it a little peaceful.
Other hot springs can be found near the canyon down Tatev Monastery, Sisian, but they are quite murky.