This famous wine cellar is hundreds of years old and is made up of 20 km of underground pipes and tunnels that are even more complex than the road network that runs above it. With a depth of more than 20 meters, most cellars lie in sandy ground and often have 3 floors. A 1.5 hour tour includes a walk around these cellars, Retz town square and an enjoyable glass of wine at the town’s wine merchant.