Temple of Diana

The Temple of Diana Nemorensis (Nemus Dianae) was part of an ancient Italic monumental sanctuary erected around 300 BC, and dedicated to the goddess Diana Nemorensis, or "Diana of the Wood". It was a popular place of worship until the late imperial age. The temple was situated on the northern shore of Lake Nemi, beneath the rim of the crater and the modern city of Nemi, which take their names from the grove of Diana. Large parts of the terraces and buildings remain today.

Source: Wikipedia (CC BY-SA 4.0) — https://en.wikipedia.org/wiki/Temple_of_Diana_(Nemi)