Boats traveling the River Marne between Meaux and Lagny-sur-Marne take a short underground passage, the 300 m long Tunnel de Chalifert. This was our fifth tunnel of our journey to Burgundy. The maps showed that there would be one more tunnel ahead.
When traveling on a river, a tunnel is unexpected; navigable rivers don’t usually just go under hills without human intervention. In this case the French engineers did intervene and the Canal de Chalifert, finished in 1846, was built to bypass a wide bend in the Marne. While most of the Marne’s water takes the long way around, boats navigate this manmade short cut. At the end of the bypass, to return boats to the river, two locks and a short tunnel, the Tunnel de Chalifert, were built.