Complex sentence: The Pagsanjan Falls stamp error refers to a error in a postage stamp issued on May 3 1932 as part of a set of seven stamps showing places of interest and landmarks in the Philippines, at that time a United States territory.
Split into simpler sentences: The Pagsanjan Falls stamp is a postage stamp issued on May 3 1932, which is notable for having an error. It is part of a set of seven stamps showing places of interest and landmarks in the Philippines, at that time a United States territory.