View of one of the twelve boundary stones that have been found around the site of Gezer—in the Shephelah of Judah.
This one is displayed in the Archaeological Museum in Istanbul.
The bottom line is written in Greek and is like those that say "[belonging to] Alkios." On the top line, upside down in the image, is a portion of a Hebrew inscription that typically says "the boundary of Gezer" (thm gzr)—that is, a portion of the name Gezer is preserved. This is about as close as one can get to a "sign" saying 'here is Gezer!'
Thanks to Todd Bolen for interpretive assistance in the proper reading of this inscription.