Domus Aurea (palace) built
64 CE.
Shown on the map at 41.891°, 12.495°.
The Domus Aurea (Latin, "Golden House") was a vast landscaped complex built by the Emperor Nero largely on the Oppian Hill in the heart of ancient Rome after the great fire in 64 AD had destroyed a large part of the city. It replaced and extended his Domus Transitoria that he had built as his first palace complex on the site.
Text from the Wikipedia article Domus Aurea, licensed CC BY-SA 4.0.