Francis Farm Petroglyphs
... that the Francis Farm Petroglyphs are among Pennsylvania's leading petroglyph sites, even though the culture of their creators is unknown?
... that the <b id="mwEqA"><a href="./Francis_Farm_Petroglyphs" id="mwEqE" rel="mw:WikiLink" title="Francis Farm Petroglyphs">Francis Farm Petroglyphs</a></b> are among <a href="./Pennsylvania" id="mwEqI" rel="mw:WikiLink" title="Pennsylvania">Pennsylvania</a>'s leading <a href="./Petroglyph" id="mwEqM" rel="mw:WikiLink" title="Petroglyph">petroglyph</a> sites, even though the <a href="./Archaeological_culture" id="mwEqQ" rel="mw:WikiLink" title="Archaeological culture">culture</a> of their creators is unknown?