Outside of Nîmes there stands a 1st-century relic of the Roman empire.
The Pont du Gard is an enormous aqueduct- 160 feet high and spans 900 feet across the river Gard. The Romans built it to bring water into Nîmes from over 30 miles away. It's a very well-preserved and maintained engineering marvel.
It's also a good place for a swim.
And if you are really brave, you can jump off the cliffside.
It's quite a bit higher than it looks.