This small temple is dedicated to the Greek god of medicine, Asclepius. You can find it in the gardens surrounding the Villa Borghese.
Design-wise it looks like it was built in the ancient Greece, with the typical Ionic style of the area. However, it was actually constructed in the 18th century, based on the design of the father and son duo of architects - the Aspruccis.
Wikipedia https://en.wikipedia.org/wiki/Temple_of_Aesculapius_(Villa_Borghese)
Address (Unnamed Road), Roma 00197, Italy
Coordinates 41°54'53.735" N 12°28'57.954" E