6. Pont du Gard via Avignon or Nimes. Pont du Gard is a jaw-dropping Roman ruin in southern France - a massive, virtually intact triple-arched aqueduct soaring over the Gard River. By some miracle of cultural sensitivity and good taste, the visitor’s center/theater/snack bar is about half a mile from the aqueduct, so when you get to the ruin itself, it’s as if the modern world doesnt exist. Swimming in the clear water of the Gard River on a hot summer day is pure magic, especially since it’s perfectly okay to swim under the 1900-year-old aqueduct itself. Pont du Gard is accessible by bus from Avignon and Nimes.