The Toynbee tiles are messages of mysterious origin found embedded in asphalt in about two dozen major cities in the United States and three South American capitals. Since the 1980s, several hundred tiles have been discovered.
Toynbee tiles
The Toynbee tiles are messages of mysterious origin found embedded in asphalt in about two dozen major cities in the United States and three South American capitals. Since the 1980s, several hundred tiles have been discovered.