The Toynbee tiles, also called Toynbee plaques, are messages of unknown origin found embedded in asphalt of streets in about two dozen major cities in the United States and four South American cities. Since the 1980s, several hundred tiles have been discovered. They are generally about the size of an American license plate (roughly ), but sometimes considerably larger. They contain some variation of the following inscription: TOYNBEE IDEA IN MOViE '2001 RESURRECT DEAD ON PLANET JUPiTER Some of the more elaborate tiles also feature cryptic political statements or exhort readers to create and install similar tiles. The material used for making the tiles was initially unknown, but evidence has emerged that they may be primarily made of layers of linoleum and asphalt crack-filling compound. Articles about the tiles began appearing in the mid-1990s, though references may have started to appear in the mid-1980s. History The Toynbee tiles were first photographed in the late 1980s, and their first known reference in the media came in 1994 in The Baltimore Sun. A 1983 letter to The Philadelphia Inquirer referenced a Philadelphia-based campaign with themes similar to those mentioned in the tiles (e.g., resurrecting the dead on Jupiter, Stanley Kubrick, and Arnold J. Toynbee) but did not refer to tiles. In the United States, tiles have officially been sighted as far west as Kansas City, Missouri, as far north as Boston, Massachusetts, and as far south as Richmond, Virginia. Since 2002, very few new tiles considered to be the work of the original artist have appeared outside of the immediate Philadelphia, Pennsylvania area, although one notable sighting appeared in suburban Connecticut in 2006, and one appeared in Edison, New Jersey in 2007. Presumed copycat tiles have been spotted in Noblesville, Indiana; Buffalo, New York; San Francisco, California; Portland, Oregon; and Roswell, New Mexico as well as a 1997 sighting in Detroit, Michigan and a 2013 sighting in Tulsa, Oklahoma. Many older tiles considered to be the work of the original tiler have been eroded by traffic, but older tiles remain in Pittsburgh, Pennsylvania; St. Louis, Missouri; Cincinnati Ohio, Cleveland, Ohio; and South America, among other locations. On June 19, 2013, tiles resembling the Toynbee tiles appeared on a street in Topeka, Kansas. They were removed by the evening of the next day. Less than a month later, on July 17, 2013, a tile resembling the Toynbee tiles appeared on a street in