Tablets served as a reminder for many of the danger that can follow earthquakes Modern sea walls failed to protect coastal towns from Japan's destructive tsunami last month. But in the hamlet of Aneyoshi, a single centuries-old tablet saved the day. "High dwellings are the peace and harmony of our descendants," the stone slab reads. "Remember the calamity of the great tsunamis. Do not build any homes below this point." It was advice the dozen or so households of Aneyoshi heeded, and their homes emerged unscathed from a disaster that flattened low-lying communities elsewhere and killed thousands along Japan's northeastern...