The Cryptoporticus Arles,a hidden gem of roman engineering
The Cryptoporticus (cryptoportico in usual English) of the Forum in Arles is an underground architectural complex dating back to the 1st century BCE. Built to support the Forum, the heart of Roman civic life, it served as a structural foundation for the public square while also providing storage and administrative spaces. This remarkable structure exemplifies the ingenuity of Roman engineering, with its carefully designed layout ensuring stability and functionality.
This Cryptoporticus has been listed as a UNESCO World Heritage Site since 1981.
The cryptoporticus consists of three vaulted galleries arranged in a U-shape, creating a robust base for the buildings of the Forum above. Today, it is one of the best-preserved examples of such infrastructure in the ancient Roman world.
Historical context: The roman forum of Arles
During the Roman period, Arles was an important city known as Arelate, strategically located on the Rhône River. The Forum was constructed in the 1st century BCE, under Emperor Augustus, as a political, economic, and social hub for the growing city.
To overcome the uneven terrain of the site, Roman architects built the cryptoporticus as a subterranean support system, enabling the Forum to be elevated and leveled. In addition to its structural function, the galleries likely served as storage spaces, housing goods and supplies essential for the city’s activities. Some historians suggest that the cryptoporticus may have also been used as a refuge during times of unrest or as housing for enslaved workers.
Architectural features
The cryptoporticus is made up of:
- Three parallel galleries connected by transverse passageways, forming a U-shape.
- Barrel-vaulted ceilings, typical of Roman construction, providing strength and durability.
- Openings for ventilation and light, ensuring the space was functional despite being underground.
- The galleries measure approximately 90 meters in length and are supported by rows of columns and arches, creating a symmetrical and visually striking design. The walls and ceilings were built using opus caementicium (Roman concrete), which was revolutionary at the time.
Decline and rediscovery
As the Roman Empire declined, the Forum and its cryptoporticus fell into disuse. Over the centuries, the structure became buried beneath newer layers of construction. It wasn’t until the 19th century that the cryptoporticus was rediscovered and excavated. Today, it offers a fascinating glimpse into the engineering and urban planning of ancient Rome.
Visit and tickets for the Cryptoporticus
The Cryptoporticus of Arles is a must-see for history enthusiasts and admirers of Roman engineering. Walking through its underground galleries provides a unique experience of stepping into the daily life and architectural brilliance of the Roman era.
Tickets can be purchased on site.
Address: Place de la République (entrance to the Town Hall)
Zip Code: 13200
City: Arles, France
Opening Hours:
November 2 to February 28: 10:00 AM - 5:00 PM
March 1 to April 30: 9:00 AM - 6:00 PM
May 2 to September 30: 9:00 AM - 7:00 PM
October 1 to October 31: 9:00 AM - 6:00 PM