Karolina Spring is a mineral water containing a large amount of magnesium (the ratio of calcium to magnesium is 2:5). It is mainly used in urological diseases and in the treatment of kidney stones, because magnesium significantly counteracts the formation of these concretions (stones).
When the spring was discovered in 1809, it was called the "New" spring. In 1811, the spring´s outlet was roofed with a dome supported by eight Corinthian columns, and the spring itself was renamed the Caroline Spring in 1819 in honour of the wife of the then Emperor Francis I, Caroline Augusta. The painter Maurus Fuchs painted a dedication scene on the ceiling of the dome with portraits of Abbot Reitenberger, Dr. Johann Josef Nehr, Count Kolowrat and Empress Caroline. Already in 1823, the painting had to be whitewashed because one of the figures was said to be not very well behaved and caused great merriment among the guests (was it not the Empress herself?). The original colonnade above the spring was in use from 1869. During the later reconstruction of the promenade in 1989, a copy of the original pavilion was built, approximately 10 m closer to the colonnade.