I found this photo on Pinterest, captioned as an “Art Nouveau door in Paris”. Art Nouveau yes, Paris, no. A few pages of scrolling through my Google reverse image search leads me to a villa in Ferrara, which is said to be a highly underrated city far less visited than Florence, (but just as fabulous).
Villa Melchiorri is the masterpiece Art Nouveau darling of Ferrrara, Italy,which was inaugurated on July 30, 1904.It was built by the italian architect Ciro Contini (1873|1952) as a symbolic reference to the profession of its client, the popular flower-grower Ferdinando Melchiorre, who according to some literature opened a flower shop there. Arrigo Minerbi ( Ferrara 1881- Padova 1960 ) are the floral decorations carved in cement, which resemble those of the bolognese architect Sironi.
Worthy of note is also the famous railing of Villa Melchiorri made by Augusto de Paoli, dominated at the top by sinuous sunflowers:elements ideals of the creation of a city-garden.
More history on the villa Italia Liberty (be sure to hit the translate button).