The small town of San Pellegrino (in the mountains to the north of Milan), has a source of water originating in a 400-metre deep aquifer at the foot of a dolomite cliff with limestone and volcanic rock; this makes for a water with a relatively high mineral content, even by Italian standards (more than 1,100 mg per litre).
San Pellegrino contains high level of sulphates in particular, and this makes it one of the few true alkaline water types. The composition of San Pellegrino was already studied in 1778. A recent analysis of this data showed that the composition has remained unchanged since then. The first famous person to lose his heart to this water was Leonardo Da Vinci, so you're in excellent company!