These mysterious tiles appear embedded into rads all over the world! The greatest concentration is in Philadelphia where I live. My band Scotchberg actually wrote a song about them. Anyway, if you have seen them, and have a picture of one, please join the group. If you would like to learn more about Toynbee Tiles, please visit www.toynbee.net (no I don't run this website, nor do I know the owner). - MoJunk