Pont de Bercy has been enlarged twice in its history. Opened in 1864, the five arch stone bridge was widened by 5m in 1904 to accommodate a second deck to carry a metro line above the carriageway. In 1986 the decision was taken to double the road capacity, to give an equal lane either side of the metro. Seen from the riverside towpath below, the join between old and new has something of a gigantic zip fastener about it – to my eye at least!
Click on the lower photo for a closer look.