The earliest traces of human occupation in Paris date back to the Romans in the 1st century BC.
The Montagne Sainte Geneviève, where the Pantheon now sits, was the heart of the Roman city.
The Roman city was named Lutetia.
It was built on a typical Roman pattern, with two major perpendicular roads - the cardo maximus and the decumanus maximus.
Today's rue Saint Jacques was the cardo maximus.
Today's rue Soufflot was the decumanus maximus.
The forum lay at the intersection of both.
The city also had an amphitheatre, still visible today : the Arenes de Lutece.
It also had Roman baths, also still visible today : the Thermes de Cluny.
An aqueduct, a chunk of which is still visible today in the Parc Montsouris, brought water into the city.
Many Roman artefacts excavated on site are now stored at the Musee Carnavalet.
The Romans were not the first occupiers of Paris.
The city was later named after the Parisii, a Gaulish tribe who lived nearby and mounted a fierce resistance against the Romans in 52 BC.
When the Romans settled in Lutetia, they did not wipe out the Parisii.
Indeed in the 18th century, while updating the choir of Notre Dame cathedral, workers discovered a mysterious stone pillar, covered in Roman and Gaulish inscriptions.
It was a gift from rich Gaulish naval merchants in the 1st century to the Roman emperor Tiberius.
It shows that Gauls and Romans cohabited quite peacefully.
It's considered the oldest monument in Paris and can be seen at the Musée de Cluny.