THE PARTHENON OF ATHENS

I think basically have the Venetians be repulsed before the cannons hit the Parthenon during the siege of 1642, and that should be enough (taking a liberally similar History then onwards). As long as no repeat version is made, the Parthenon should remain pretty much intact until the present day, with the mosque probably being dismantled in the mid-late 1800s.
 
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