With a guide from the association l'Araire, discover a majestic Roman hydraulic structure: the Roman aqueduct of Gier. 1h30 visit to understand its history and its operation partly underground but also aerial. With 86 km, it is the longest aqueduct leading to Lugdunum. It started from Izieux in the Loire, at the foot of the Pilat massif, thanks to a catchment in the river Gier. Several remains are still visible today and especially in the town of Mornant. On the site of the Mornantet, you will discover a complete arch and a pillar, all covered with the facing "opus reticulatum. The visit will continue with the canal which at this point begins its crossing of the village underground. Finally, you will be seduced by the deepest manhole of the Mornant tunnel that allowed the Romans to access the inside of the canal for its construction and maintenance.