The Baths of Nero are an archaeological site near the Porta a Lucca in Pisa, then the Roman city of Colonia Pisana. Now below street level, they are the only Roman remains still standing in the city and form a thermae complex.
Wikipedia https://en.wikipedia.org/wiki/Baths_of_Nero_(Pisa)
Address 14 Largo del Parlascio, Pisa 56127, Italy
Coordinates 43°43'20.204" N 10°24'7.078" E