From Ohio History Central
Inscription Rock is located in Erie County on Kelleys Island. It is one of Ohio's most famous rock art sites. Ancient Indians engraved more than one hundred designs onto a huge limestone boulder on the south shore of the island. The symbols are called "petroglyphs" from the Greek words for rock writing.
There was once another boulder with petroglyphs along the north shore of Kelleys Island, but workers quarrying the limestone blasted it apart with dynamite in the mid-nineteenth century.