In the time of medieval Bosnia, in the year 1349, Stjepan II Kotromanić began constructing the town of Bobovac. At that time, Bosnia was a banate, and it became a kingdom in 1377, with the town of Bobovac serving as the military and administrative center where the Bosnian royal crown was kept. Bobovac became known as the "royal town," a title it holds even today, and the water that the kings drank at Bobovac also became famous as the water that kings drink or "royal water." The "royal" water from the Radakovica spring bears the year 1377 in its name, celebrating Bosnia as a kingdom, with the royal town of Bobovac, which was primarily the residence of the Bosnian kings and, of course, the town from which they governed the Kingdom of Bosnia. The purity of water indicates how well it is protected from environmental influences. Water purity is determined by measuring the amount of nitrate, an inorganic compound consisting of one nitrogen atom and three oxygen atoms. Nitrate easily transfers from soil into water. Due to heavy rains or irrigation, this substance can reach the soil below the root zone and find its way into groundwater. In its natural state, water contains less than 1 mg/l of nitrate. A level above this indicates contamination caused by fertilization, animal waste, decaying plants, septic tanks, or sewage systems. The nitrate level in water can only be determined through analysis, as nitrate has no taste, smell, or color. The World Health Organization recommends that exposure to nitrates should not exceed 50 mg/l over short periods of time. Nitrate cannot be removed from water by standard water softeners and filters, including activated carbon filters, nor by boiling the water. The following system describes the purity of bottled water. Royal water from the Radakovica spring belongs to the superior five-star category of water, with an exceptionally low measured nitrate level of 0.21 mg/l. Modern methods of detailed water quality testing have confirmed the special quality and exceptional purity of the water from the Radakovica spring, which has been recognized by the people living in this region since ancient times.