Caelian Hill in the context of "Porta Capena"

The Oppian Hill (Latin, Oppius Mons; Italian: Colle Oppio) is the southern spur of the Esquiline Hill, one of the Seven hills of Rome, Italy. It is separated from the Cispius on the north by the valley of the Suburra, and from the Caelian Hill on the south by the valley of the Colosseum. The Oppius and the Cispius together form the Esquiline plateau just inside the line of the Servian Wall.

In the divisions of the Septimontium (seven hills) Fagutal appears as an independent locality, which implies that originally "Oppius" was strictly applied to this spur except the western end. The northern tip of this western end was also called Carinae, which extended between the Velian Hill and the Clivus Pullius, looked out to the southwest (across the swamps of the Palus Ceroliae towards the Aventine), incorporated the Fagutal and was one of ancient Rome's most exclusive neighborhoods.

The Apostolic Palace of the Lateran (Latin: Palatium Apostolicum Lateranense), informally the Lateran Palace (Latin: Palatium Lateranense; Italian: Palazzo del Laterano), is an ancient palace of the Roman Empire and later the main papal residence in Rome.

Located on Saint John's Square in Lateran on the Caelian Hill, the palace is adjacent to the Archbasilica of Saint John Lateran, the cathedral church of Rome. The wealthy Lateran (Laterani) family held the palace estate during the Roman Empire, and the estate eventually came into the hands of the Emperor Constantine the Great who gifted it to Pope Miltiades who was residing at the Basilica of Santa Pudenziana.

The Septimontium was a proto-urban festival celebrated in ancient Rome by montani, residents of the seven (sept-) communities associated with the hills or peaks of Rome (montes): Oppius, Palatium, Velia, Fagutal, Cermalus, Caelius, and Cispius. The Septimontium was celebrated in September, or, according to later calendars, on 11 December. It was not a public festival in the sense of feriae populi, according to Varro, who sees it as an urban analog to the rural Paganalia.

The etymology from septem ("seven") has been doubted; the festival may instead take its name from saept-, "divided," in the sense of "partitioned off, palisaded." The montes include two divisions of the Palatine Hill and three of the Esquiline Hill, among the traditional "seven hills of Rome".

Monti is the 1st rione of Rome, Italy, identified by the initials R. I, located in Municipio I. The name literally means 'mountains' in Italian and comes from the fact that the Esquiline, the Viminal Hills, and parts of the Quirinal and the Caelian Hills belonged to this rione: currently, however, the Esquiline Hill belongs to the rione Esquilino.

The coat of arms consists of three green mountains with three tops on a silver background.

Caelius Vibenna (Etruscan Caile Vipina) was a noble Etruscan who lived c. 750 BCE (but see below) and was a brother of Aulus Vibenna (Etruscan Avile Vipina).

Upon arriving at Rome, Vibenna was a friend of the sixth king of Rome Servius Tullius. He and his brother Aulus are also recorded as having aided King Tarquinius Superbus, although Tarquinius Superbus lived some five generations after Romulus. Tacitus relates that a certain hill in Rome, previously named Querquetulanus (after the oak trees covering the hill) was renamed the Caelian Hill after Caelius Vibenna.