A tiny village in Japan would've been wiped out by the tsunami had they erected their houses closer to the sea-views. However, they chose to abide by ancient tsunami-warning stones that carried the messages of their forefathers, and survived. Like an ancient message board.
These 10 feet-tall tsunami stones are sprinkled all over the coastal regions of Japan; some having been stuck into the ground and carved with warning messages and advice over 600 years ago. In the village of Aneyoshi's case, the waves stopped only 300 feet before the stone, saving 11 households (though they weren't entirely untouched—one mother and her three children were killed in their car, driving in a nearby town.)
Itoko Kitahara, who works at Kyoto's Ritsumeikan University and specializes in natural disasters, said that "some places heeded these lessons of the past, but many didn't." Unfortunately some of the stones were swept away in March's tsunami, but it's unlikely their messages won't reach future generations of coastal-dwellers. [NY Times]