French amateur archaeologist Bruno Tassan fights to preserve a neglected 2,000-year-old ancient interstate in southern Provence At first glance, it didn't appear that impressive: a worn limestone pillar, six feet high and two feet wide, standing slightly askew beside a country road near the village of Pélissanne in southern France. "A lot of people pass by without knowing what it is," Bruno Tassan, 61, was saying, as he tugged aside dense weeds that had grown over the column since he last inspected it. Tassan was showing me a milliaire, or milestone, one of hundreds planted along the highways of Gaul...