Joys and Benefits of Hot Springs
Water that flows up from underground to form a hot spring often picks up traces of minerals from the rock through which it passes. The result is hot, mineral-laden water, but this is not “mineral water” for drinking! Instead, it is for soaking (hot spring baths are for soaking, not bathing), and Japanese people ascribe all sorts of restorative and curative properties to these baths, including improvement of skin conditions and internal maladies. Thus, most public hot springs and hotel baths advertise the mineral content of their water.
Even thermal springs (baths that have little or no mineral content) are still very effective for alleviating stress. Japanese customarily soak up to their necks for 10 to 30 minutes, relaxing both muscles and nerves, and helping to melt away stress. In many hot spring towns, you will find public foot baths (ashi yu) where you can sit and soak your feet.
Whatever kind of bath you find, by all means try this custom for yourself.