An impressive – if rather confusing – sprawl of ruins, the Roman Forum was ancient Rome's showpiece centre, a grandiose district of temples, basilicas and vibrant public spaces. The site, which was originally an Etruscan burial ground, was first developed in the 7th century BC, growing over time to become the social, political and commercial hub of the Roman empire. Landmark sights include the Arco di Settimio Severo, the Curia and the Casa delle Vestali.
Like many of ancient Rome's great urban developments, the Forum fell into disrepair after the fall of the Roman Empire until eventually it was used as pasture land. In the Middle Ages it was known as the Campo Vaccino ('Cow Field') and extensively plundered for its stone and marble. The area was systematically excavated in the 18th and 19th centuries, and excavations continue to this day.
Entering from Largo della Salara Vecchia – you can also enter directly from the Palatino or via an entrance near the Arco di Tito – you'll see the Tempio di Antonino e Faustina ahead to your left. Erected in AD 141, this was transformed into a church in the 8th century, the Chiesa di San Lorenzo in Miranda. To your right, the 179 BC Basilica Fulvia Aemilia was a 100m-long public hall with a two-storey porticoed facade.
At the end of the path, you'll come to Via Sacra, the Forum’s main thoroughfare, and the Tempio di Giulio Cesare (also known as the Tempio del Divo Giulio). Built by Augustus in 29 BC, this marks the spot where Julius Caesar was cremated.
Heading right up Via Sacra brings you to the Curia, the original seat of the Roman Senate. This barn-like construction was rebuilt on various occasions before being converted into a church in the Middle Ages. What you see today is a 1937 reconstruction of how it looked in the reign of Diocletian (r 284–305).
In front of the Curia, and hidden by scaffolding, is the Lapis Niger, a large piece of black marble that's said to cover the tomb of Romulus.
At the end of Via Sacra, the 23m-high Arco di Settimio Severo is dedicated to the eponymous emperor and his two sons, Caracalla and Geta. It was built in AD 203 to commemorate the Roman victory over the Parthians.
In front of the arch are the remains of the Rostri, an elaborate podium where Shakespeare had Mark Antony make his famous 'Friends, Romans, countrymen…' speech. Facing this, the Colonna di Foca (Column of Phocus) rises above what was once the Forum's main square, Piazza del Foro.
The eight granite columns that rise behind the Colonna are all that remain of the Tempio di Saturno, an important temple that doubled as the state treasury. Behind it are (from north to south): the ruins of the Tempio della Concordia, the Tempio di Vespasiano, and the Portico degli Dei Consenti.
From the path that runs parallel to Via Sacra, you'll pass the stubby ruins of the Basilica Giulia, which was begun by Julius Caesar and finished by Augustus. At the end of the basilica, three columns remain from the 5th-century BC Tempio di Castore e Polluce.
Nearby, the 6th-century Chiesa di Santa Maria Antiqua is the oldest and most important Christian monument in the Roman Forum. The church, which is occasionally opened for temporary exhibitions, is a treasure trove of early Christian art with exquisite 6th- to 9th-century frescoes and a hanging depiction of the Virgin Mary with child, one of the earliest icons in existence. Accessible from in front of the church is the Rampa Imperiale (Imperial Ramp), a vast underground passageway that allowed the emperors to access the Forum from their Palatine palaces without being seen. It's not all open but you can walk up to a panoramic viewing balcony.
Back towards Via Sacra is the Casa delle Vestali, home of the virgins who tended the sacred flame in the adjoining Tempio di Vesta. The six virgin priestesses were selected from patrician families when aged between six and 10 to serve in the temple for 30 years. If the flame in the temple went out the priestess responsible would be flogged, and if she lost her virginity she would be buried alive. The offending man would be flogged to death.
Continuing up Via Sacra, past the circular Tempio di Romolo, you'll come to the Basilica di Massenzio, the largest building on the forum. Started by the Emperor Maxentius and finished by Constantine in 315, it originally measured approximately 100m by 65m.
Beyond the basilica, the Arco di Tito was built in AD 81 to celebrate Vespasian and Titus' victories against rebels in Jerusalem.