Complex sentence: The Caelian Hill (Latin "Collis Caelius", Italian "Celio") is one of the famous Seven Hills of Rome, and was in Republican-era Rome a fashionable residential district and the site of residences of the wealthy.
Split into simpler sentences: The Caelian Hill (Latin "Collis Caelius", Italian "Celio") is one of the famous Seven Hills of Rome. In Republican-era Rome the Caelian Hill was a fashionable residential district and the site of residences of the wealthy.