The Le Guétin Canal Bridge is an aqueduct which carries the Loire Lateral Canal over the river Allier. The viaduct is 343 metres long and 9.33 metres wide, and carried on 18 arches built in 1838 to replace a dangerous crossing which involved a series of locks down from canal level, across a sometimes very fast flowing river, and up the other bank.
It is difficult to convey in a photo how big it is.
We passed the aqueduct on our way to Switzerland, and this was one of the inpromptu stops that turned a normally 7 hour journey into a 10 hour exploration. We weren't in a rush.