The Great Onofria Fountain, also called the Great Well of Onofria, was designed and built in 1438 by the Onofrio Giordano della Cava architect from Naples, to whom Dubrovnik owes its municipal water supply system. The fountain is located in the center of the old town, near the Pile Gate in the courtyard of the Monastery of Poor Clares. The rotunda-shaped building has 16 stone mascarons, from whose throats spring water is poured.
Originally, the well was richly decorated, but after a catastrophic earthquake in 1667, its utility was restored, but the decorations were not restored. It was part of the municipal water system built in the first half of the 15th century, consisting of the Great and Small Onofria Fountain and many small fountains scattered throughout the city.
Prior to the construction of the water supply system, one of the main ways of obtaining drinking water in Dubrovnik was collecting rainwater, which was collected in stone tanks. During periods of drought, water was delivered by ship from a source in Milini. Thanks to the Onofrio della Cava project, water flowed into the city from sources of the Dubrovačka River 12 km away. The architect used the natural decline of the area, which today allows the use of water without the help of pumps.