Icon under a microscope

this landmark is iconic and easily recognisable when you see the whole picture, but can you identify it from this small portion of the image?

Intricately carved, this fountain is the most iconic in the city and was built at the terminal point of the Acqua Vergine, one of the city’s most important modern aqueducts.

Work began on the fountain in 1732 and was completed in 1762 and depicts the god of water.