I have to admit, that up until very recently I wasn't entirely sure what mineral water was all about. I can recall the use of it in the classic 1980's movie, "Heathers," but that's about it. (For those that don't remember, in the film it's a sign of how backward and homophobic the town was, as consumption of this beverage made folks automatically question one's sexuality.) Well, basically, mineral water is simply water that has minerals in it, such as salts and sulfur compounds. Certain areas in the world are famous for their mineral water sources, as these were often supposed to have medicinal and healing qualities. Spas often sprung up around them, and then people started to bottle and sell these waters. Some are naturally carbonated.
Obviously, Slovenia has some of these naturally occurring mineral water sources. The brand I bought was Radenska. In addition to marketing a few types of mineral waters, they also make flavored waters (their Oaza line), and carbonated soft drinks (their Ora line). The former includes some exotic flavors, such as thyme, linden/honey/lime (linden is a tree sometimes used in herbal teas and tinctures), and elderflower and white tea. I thought I was trying two types of mineral water, but alas I was careless and bought two bottles of the same kind by mistake, as the labels were slightly different. So the only kind I was able to locate was their classic mineral water. This beverage has high concentrations of calcium and magnesium in it. Which is also the distinction of what constitutes "hard" water. "Soft" water is water with low concentrations of magnesium and calcium. (And evidently waters with a moderate amount of these substances are just "semihard, regular" water, I guess.) If your home water supply is "hard," that can have negative effects. Boilers' function may be affected, and household pipes may get clogged with mineral deposits. Also soap may not lather properly in dishwashers and washing machines. (Alternately, I've stayed in some hotels with overly "soft' water, which is unpleasant, too. It feels greasy--like you still have soap on your hands even after rinsing thoroughly.)
Anyway, I tried the classic Radenska, which came in a 1.5 liter plastic bottle, and a 1 liter glass bottle. I had it chilled, but plain, and then over ice. I could tell a difference between this and regular tap water. Not really in a good way. It wasn't as refreshing, somehow, as normal water. A major factor was probably the carbonation. Plus, to be fair, I think I've tried domestic mineral waters in my life, and came away similarly unimpressed. So, while I didn't like it, and wouldn't recommend it, maybe avid mineral water drinkers would enjoy it. (My father, for example, said he liked it just fine.)
Finally, to throw out some very brief info about the country of Slovenia, it gained its independence from the former Yugoslavia in 1991. In 2004 the nation joined NATO and the European Union. And the 2012 Global Peace Index rated them as one of the world's most peaceful countries.