A fountain or a piece of art? Probably both. The Fountain of the Lions was built in 19th century on Praça de Gomes Teixeira just opposite the Carmo Church and as its name suggests, it is decorated with four winged lions.
Wikipedia https://en.wikipedia.org/wiki/Fountain_of_the_Lions_(Porto)
Address 17 Praça de Gomes Teixeira, Porto 4050290, Portugal
Coordinates 41°8'49.624" N -8°36'56.214" E