Trap streets and towns are non-existent streets and towns that cartographers put into their maps in order to prove copyright. If another map maker also included those fake features, then the orginal cartographer could "trap" the copier -- prove that they had violated copyright. This was a fairly wide-spread practice, although only a few instances are well-known. The Earth Sciences & Maps Library holds some examples of maps that contain map traps:
Agloe, NY -- This was a trap town inserted into map of New York state by two cartographers at the General Drafting Company in the mid 1930s.
La Taza Drive, Upland, CA -- The Thomas Brothers guides are classic road guides to California towns and streets. In a 1981 interview with the Los Angeles Times, [someone], the current editor of the Thomas Guides, admitted that their company regularly introduced trap streets into their guides. The older San Bernardino County guides alone are rumored to contain more than 100 trap streets! One such street that people have noted is the non-existent La Taza Drive, at the northern end of Wilson Avenue in Upland, CA. In the 1993 edition held by the Earth Sciences & Map Library, La Taza appears right on Page 1! On the later 2005 edition, La Taza Drive has disappeared -- the 210 freeway runs through, instead.
Credit for the lead to: Gayomali, Chris. (2013, March 29). Trap streets: The crafty trick mapmakers use to fight plagiarism. TheWeek.com. http://theweek.com/article/index/241967/trap-streets-the-crafty-trick-mapmakers-use-to-fight-plagiarism
Sandy Island -- Also labeled as Sable Island on some maps, Sandy Island first began appearing on nautical charts in the 1860s. Located between New Caledonia and the eastern coast of Australia, the island was represented to be the size of Manhattan. Not until the late 1990s and early 2000s did we definitively decide on its non-existence.