Naples Mound 8 is a major Havana Hopewell burial mound on the Illinois River bluffs in western Illinois and the largest known bluff-top mound in the lower Illinois Valley. It entered written history in 1834, when members of Zion’s Camp led by Joseph Smith dug into it after noticing bones, an episode later remembered as the Zelph Mound incident. Antiquarian excavations in the late 19th century led to Smithsonian involvement, and archaeologists relocated the mound in 1974. Later work confirmed it as a Hopewell burial mound within the Napoleon Hollow Archaeological District, used roughly between 50 B.C. and A.D. 100, with evidence of far-reaching exchange networks.