This 1974 Denver Lincoln Memorial Penny features a rare error on the reverse side. The coin was struck with a die that bore an image of the Lincoln Memorial that is common in the previous year. This error makes the coin a unique addition to any collection of US coins, particularly for collectors interested in error coins. I've collected about a dozen of the 1973 Denver that have this error and seen many, but I have never seen one in a 1974 Denver. In the research, this error on the 73 is unknown according to the books written for all errors known.  This Lincoln is truly unique.