Clue #2, The Revealer: From a place and time, that will change your mind

Here is clue # 2 about this Thursday's installment of "The Revealer":

This week’s segment somehow brings together two well-known ancient cultures, Charles Darwin, a quarry and transportation. We're hoping that these clues plus seeing a little more of the above photo help you guess the time, place or subject we’re bringing you this week.

Put your guess in the comments section and be sure to see “The Revealer” live on Back|Story this Thursday at 2300 CET/1700 EST.

(Tomorrow we'll provide you with a different clue that could help unravel more of the mystery.)