Each time we pass through the area just to the north of Aix-en-Provence on the TGV, I see off to one side (the right side as you're heading southbound) in a little valley, what appears to be a Roman aqueduct. I never manage to quite get a clear shot of it; either the weather or the lighting is uncooperative, or we are moving too quickly and the picture doesn't come out well.
Today on the trip back to Paris from Saint Raphaël, FINALLY:
I have known that there is an actual Roman aqueduct somewhere in that general area, but when I checked a map, it turns out that the Pont du Gard (the real Roman one) is too far from where I regularly spot the other one. So, a bit more digging revealed that the one I've been seeing is called the Aqueduc de Roquefavour and it's near Ventabren, and only about 1 kilometer from the TGV tracks which explains why I was able to get a picture at all.
It's not so old as to be Roman, as construction on it only started in 1841, but it IS now classified as a historic monument. Its design was inspired by the Pont du Gard but it is nearly two times higher; in fact, it seems to be the highest stone aqueduct in the world. It is also a functioning aqueduct, being part of the Canal de Marseille, which takes water from the Durance river (a major river that flows through Provence and connects with the Rhône) into Marseille.
You have to admit: those Romans sure knew what they were doing.