Forum of Arles, Roman forum in Arles, France

The Forum of Arles is a large paved square surrounded by four monumental colonnaded halls connected by vaulted galleries. Beneath this plaza lie underground passages called cryptoporticos, which are open to visitors and show how the Romans engineered the site.

The forum was built between 30 and 20 BCE as the first major construction project of the Roman colony. It was created shortly after the city's founding to demonstrate Roman power and prosperity in the region.

The forum's name survives in today's Place du Forum, though the Roman square lay further south, behind the two columns and half entablature built into the facade of the Hôtel Nord-Pinus. A marble copy of the clipeus virtutis, the golden shield awarded to Octave by the Senate in 27 BCE, was set up here; the copy, dated 26 BCE, was found in 1951 at the east end of the cryptoporticus's north branch.

The plaza is easily reached in central Arles and can be viewed for free, while the underground cryptoporticos are accessible through the town hall. Wear comfortable shoes, as the ground can be uneven and the underground stairs are narrow.

The underground cryptoporticos were engineered to level out the slope of Hauture hill beneath the plaza. This clever solution allowed the Romans to create a flat plaza on uneven terrain and is still visible in the passages today.