From an earlier version of the Wikipedia page 
The Bourne Stone is an archaeological curiosity located in the town of Bourne, Massachusetts.
The object is a 300-pound chunk of pink granite, upon which two lines of carvings were made. For many years it served as the doorstep for a meetinghouse in Bourne. It is currently on display at the museum of the Bourne Historical Society.
The controversial amateur epigrapher Barry Fell claimed that the carvings were made in Iberian script and read as follows:
'A proclamation. Of annexation. Do not deface. By this Hanno takes possession.'
Fell asserted that "Hanno" referred to Hanno the Navigator, which, if true, would date the stone to about 570 BC and offer evidence that the Carthaginians crossed the Atlantic in ancient times.
In 2004 runic expert Michael Barnes was shown the stone and stated that the markings were definitely not runes, and the Minnesota archaeologist Patricia Emerson and Larry J Zimmerman (an academic with expertise in Native American archaeology) suggested that the markings were either natural or Native American petroglyphs.