their bulletin board
... that Athenians built their bulletin board with a surprising lack of precision?
... that <a href="./Classical_Athens" id="mwA8c" rel="mw:WikiLink" title="Classical Athens">Athenians</a> built <b id="mwA8g"><a href="./Monument_of_the_Eponymous_Heroes" id="mwA8k" rel="mw:WikiLink" title="Monument of the Eponymous Heroes">their bulletin board</a></b> with a surprising lack of precision?