Located on the Loing river, the Saint-Mammès lock was built in 1724. It is an exception on the Loing canal as it has embanked walls and is not stone-faced.

With a length of 30 meters, building started 1724 and it is extended by a dam. In 1890, it was enlarged to accommodate boats with a length of 38.50 meters. A reproduction of one of the mobile elements of the old dam was created to present its particular process. The principle was simple : these elements were side by side, allowing a dam to be formed, with a bridge above to cross over the canal or to enable lock keepers to manoeuver the panels. It is no longer in use, but remains an important element of our common waterway heritage.

In the context of its preservation, the municipal council decided to have it restored just as it was before. The main stages of reconstruction in the first half of 2013 were :
 Desilting of the airlock (between the two lock gates),
 Renovation of two existing lock doors,
 Recovery of sandstone pavements on the dock and the pier,
 Replacement of the existing lock path with a new one (width of 1.40 meters without projection)
 Building of a gatehouse identical to the original one (dressing with earthenware plates, covered by slate roof), facing the gatehouse located on the opposite bank of the Loing, which was also in use when the lock and dam existed.
 Installation of information panels relating the lock’s history, how it operated and generally the history of the Loing canal.