The Fonte dos Leões [Fountain of Lions] is a monumental fountain 8 metres wide and 6 metres tall, integrated in the water supply system of Porto during the 1880s. It was awarded to the French company Compagnie Générale des Eaux pour l'Etranger, also responsible for the construction of this public equipment. Approved in 1885, it came into operation from the next year on. This fountain, besides decorating the Praça dos Voluntários da Rainha [a square], provided the required ventilation and oxygenation of the water, and provided relief to pipes under pressure.
The Fonte dos Leões consists of an octagonal tank in granite, with rounded edges and exterior walls of corrugated iron, and a central fountain in bronze, painted with four winged lions sitting on its edges. It is surmounted by two overlapping and staggered round pool structures; the lowest one has a frieze with plant elements and horns from which water flows, and is pinnacle shows a kind of pine cone.
At first, water was brought from the Santo Isidro reservoir, and later, from 1942, the Fonte dos Leões was supplied from its own storage tank, in granite, a few metres away from the fountain. Old pictures show that, at first, the fountain used to have an iron railing protecting it.