Cryptoportique

The Cryptoportiques of Arles are an underground network of vaulted galleries beneath the centre of the old town, and they are among the most unusual Roman monuments in France. They were built in the first century BC, soon after Julius Caesar founded the Roman colony of Arelate, and their purpose was practical. The Roman forum, the main public square of the city, stood on ground that sloped down toward the Rhône, and the engineers solved the problem by building a platform over a set of deep galleries that levelled the site and carried the buildings above. The word cryptoporticus means a covered or hidden passage, and these galleries form a U-shaped plan, with two long parallel galleries joined by a third, covering about 3,400 square metres at a depth of several metres under the present streets.

Walking through them, you notice the scale and simplicity of the work. Massive barrel vaults of stone rise over broad corridors, and the galleries are divided by rows of heavy piers pierced by arcades, so that the space is a series of rhythmic archways. Small openings in the roof and ventilation shafts let in limited light and air, and the cool temperature stays more or less constant through the year, so the galleries are a welcome relief on a hot summer day. The atmosphere is dim, silent and slightly mysterious, and visitors often lower their voices.

The galleries had several roles over the centuries. Scholars think that they served as storerooms for goods, possibly grain, as well as acting as a foundation, and in later periods the spaces were used as cellars, as shelters in wartime and as places for storage. The entrance is inside the town hall, on the Place de la République, and you reach it from the Place du Forum, the square where the forum once stood. Above ground, two Roman columns from the temple that stood on the forum are still visible, built into the facade of a hotel on the square, a reminder of what lay above the galleries.

Arles has several Roman monuments, and the cryptoportico belongs to the group that UNESCO listed in 1981 as the Roman and Romanesque monuments of Arles. A visit takes about an hour, with seasonal opening times, and a combined ticket for several sites is usually available. Wear a light jacket, since the galleries are cool.

The cryptoportico suits those interested in Roman engineering, families with children who like exploring underground, and visitors who want a quiet place in the middle of a busy town. The Arles Amphitheatre, the Théâtre Antique and the Church of St. Trophime are a short walk away.